Not Quite Canon: MI GO for D&D adjacent.

I did this - once upon a time.
I think I painted it with a wooden skewer on (what looks like) a bit of a box.

I like the Mi Go, and I think that they should be able to turn up in pretty much any setting or genre that doesn't specifically exclude them.

These are 'common' Mi Go - they come from 'Out There' but are not ultraterrestrial horrors from an anti-matter universe.

Converting from Call of Cthulhu 5e, we get the following D&D-adjacent Mi Go:

AC +2     HD 2     Mv. 75% Normal Human (Flying 125% Normal Human or 75% Bat)     ML 8

• 1 nipper attack for d6 hits, or by weapon, or grapple (then drop you from a great height)
• the AC bonus is for a high average Dex, and they can wear armour 
• average Int is 13, with a 25% chance of being able to cast d3 spells (or same % of 1-3 caster levels, though that's much the same)
• any Mi Go weapon (including all but the most straightforward hand weapons) has a 40% chance of being used incorrectly by a human - 50/50 it's aimed at the wielder/ aimed at the floor
• they are unaffected by silence/deafness and darkness/blindness because of their weird eyeless heads - you might choose to extend this to all visual and aural effects, including illusions
• my gut tells me that Mi Go are familiar with psionics, but might not be psionicists - they might even be completely immune and unable to use them

This is a fairly typical conversion profile for a CoC monster with human-range characteristics (compare to Ghouls and Serpent People), so you might want to tweak it depending on your vision for the Mi Go - those from the old AD&D Deities & Demigods are stupid giant space lobsters that communicate by clicking their nippers.

If you kill one of these Mi Go...

1. It bubbles and rots away in 1 round, leaving a slimy puddle.
2. It abruptly transforms into dense mineral - Dex check at -3 or the killing weapon is stuck. It crumbles to dust in 1-4 rounds.
3. Its flesh blackens and shrivels away, leaving an apparently human skeleton - on the next round, the bones explode for 1-6 hits to all within 10'.
4. It dissolves into a 10' acid pool that evaporates in 1-6 rounds - d8 hits per round and you have to throw away your boots.
5. It bursts into flames, causing 2-8 hits to all within 10'.
6. It transforms into a lifeless duplicate of whoever struck the killing blow, appearing to be a normal dead body in all respects until it disintegrates into black soot after 3 days.

These are Draconian death-throes, from Dragonlance, and I think they suit the weird alien/ 'mysterious Little People' Mi Go just fine.

To these Mi Go, human brains are...

1. Delicious, extracted messily in 1-4 rounds.
2. A delicacy if prepared correctly, extracted carefully over 1-4 turns.
3. Crude computers for their organic robots, shelled like peas in 1-4 rounds.
4. Part of their dastardly plans for infiltration and conquest, carefully removed and sustained with uncanny surgery over 1-4 turns.
5. The raw material for spawning servitors and minions, harvested enthusiastically in 1-4 rounds.
6. Delicate experimental subjects for developing psionic biotechnology, painstakingly and reverentially separated from their host over 1-4 turns.

They definitely want brains, of that I'm sure.

The hummadruz of these Mi Go...

1. Makes humans of 0-1st level drowsy - save vs. spells at +2 per round or nod off; they will have forgotten the 2 minutes prior to nodding off (AD&D 1e forget spell).
2. Hits the Brown Note - save vs. paralysis each round or become nauseated/sick (BECMI Centipede venom, Cave Locust spit, Troglodyte stench etc.) and you have to throw away your underwear.
3. Makes eyes vibrate, ears buzz and noses tickle - save vs. paralysis each round or be afflicted by AD&D 1e blur spell.
4. Fills you with unease and intrusive thoughts - save vs. spells each round or be subject to fear.
5. Prevents spoken, written, telepathic and electronic/mechanical communication.
6. Causes bleeding from every orifice - 1 hit per round, plus save vs. effects as 2 above.

It might require several Mi Go to produce an effective hummadruz - it might even just be a secondary effect of their mass presence in an environment. HPL's The Whisperer in Darkness suggests it can be used by human agents of the Mi Go (presumably through surgical modifications).

In addition to any hand weapons and projectiles, some of these Mi Go are armed with...

1. Energy Mantles: + 5 AC, +5 to all saves; if you strike them, take 2-12 hits plus save vs. paralysis or stunned 1-4 rounds; primarily defensive, but they can make a touch attack vs. unarmoured AC with the same effect; can levitate 12 turns/day, capable of leaving planetary atmosphere/gravity and can sustain one air-breathing prisoner/passenger.
2. Flame Pistols: 1-6 charges, fires a 20' streamer of burning gas for 2-12 hits.
3. Shock Pistols: 1-8 charges, fires a 20' burst of blue sparks for 1-4 hits, but you must also save vs. death (or your heart stops, go to 0 hp) and save vs. paralysis or stunned 1-4 rounds.
4. Cloaking Devices: non-magical illusion to appear as a humanoid up to 10' tall; cannot be disbelieved, can only be seen through with truesight or second sight. Anyone looking at them with dark- or infra-vision will also be fooled, but must save vs. paralysis each round or be affected as hummadruz result 3.
5. Hypnotic Lanterns: flickering blue-white octagonal cylinder mounted on a pole; save vs. spells at +2 each round or fall under non-magical hypnosis - cannot look away from the Lantern and will move as directed by the Mi Go (perfect for brain extractions). Anyone with dark- or infra-vision looking at the Lantern must save vs. paralysis each round or roll 2d3 against the hummadruz results above.
6. Personal Force Fields: protection from normal missiles, resist cold/fire, +3 AC, +1 to all saves, repel anyone within 5' once per round, hurling them 20' for 2-7 hits unless they save vs. dragon breath; can levitate 6 turns/day, but cannot use repel attack while doing so.

Wot no mist projectors or living armour? They're not compulsory.

The purpose of these Mi Go is...

1. To civilise the savages.
2. To domesticate the animals.
3. To uplift the primitives.
4. To extract rare resources.
5. To go boldly/ "What Is This Earth Thing You Call Kissing?"
6. To exterminate all the brutes.

If it isn't clear, by savages, animals, primitives and brutes, I mean you humans. Emergent psychics and/ or spell-casters might be rare resources.

In human terms, these Mi Go are...

1. Absent-minded professors.
2. Evangelists of galactic transhumanity.
3. Unsentimental project managers.
4. Millennially patient and reclusive.
5. Benevolent colonisers heartbroken to punish you for your ingratitude.
6. Full-on Mars Attacks space-bastards.

Even though they seem like the kind of monster that might not, roll Reaction for Mi Go -  though ultimately they aren't really Friendly at all, and their Neutrality can get very chilly, very fast. 

In this case, the Mi Go are fronted by...

1. Scro (Spelljammer space orcs).
2. Mind Flayers and/or Doppelgangers.
3. Oards (BECMI module Where Chaos Reigns).
4. Human agents/cultists (up to and including national governments and 'deep states').
5. Elves.
6. Dragons and/or Githyanki (1st edition AD&D, when they were pals with Red Dragons).

There doesn't need to be a front, and the fronts may use fronts of their own, but Mi Go will always have some indigenous allies, agents or servitors.

Old School Druid Class (wip) - Atheist/BOSR/Folk Horror/Pagan/Psychedelic/Witch

This Druid is the Dionysus to this Cleric’s Apollo, and this Druid from Basic Red is a significant recent ancestor/inspiration - I was never that keen on the medieval environmentalist take.

The BECMI (or B/X) Cleric class is the template, including spell-casting not being available until 2nd level.

The Wicker Man (1973)

Description: The Druid class is defined against the Cleric, being the pagans, shamans and witches observing the Old Ways, in defiance of the True Faith and the Universal Church. Druids are not the Clerics of another religion, though some are part of priestly traditions.

The Old Ways are a sprawling array of belief systems, without any overarching harmony or hierarchy, though they tend towards a strong relationship with the elemental, natural and supernatural worlds - whether through appeasement, domination or veneration. 

A Druid does not necessarily identify as a Druid - it's a metagame term of convenience. Not all Druids know they are Druids, some will reject the label, and define themselves within their own milieu.

Within the class, there will be those who do not make full use of the special abilities - if you don't know you can Call the Wild and the Weird, you won't try; if you only get naked and high for fun, you might not notice you can Pass Without Trace.

XP, Saving Throws, Attacks & Hit Dice: all as Cleric. 

Prime Requisite: equal chance (roll d6) of any, with usual benefits/penalties – but you do this after you’ve rolled your Ability Scores and chosen Druid as your class. 

Your Prime Requisite will reflect in how your special abilities manifest, the way you carry yourself, your choice of equipment, and the nature of any uncanny forces that take an interest in you.

If you are in an Altered State, you can count a negative Prime Requisite adjustment as positive when using Druidic special abilities.

I don't know who they are or what they're doing, but they look the part, don't they?
Britannia (2018 onwards)

Armour: Any, but you can’t use your Druid special abilities while wearing iron or steel armour, or armour you didn’t make yourself or strip from a defeated foe.

A naked Druid in an Altered State counts as carrying a shield if wielding a staff weapon, and can also use their Prime Requisite modifier as an AC bonus and for saves vs. fire, frost, poison and lightning.

Kill List (2011)

Weapons: Any, but you can’t use your Druid special abilities while armed with iron or steel weapons that have not been wetted with blood in the last minute. Must be at least a dagger-cut's worth. 

Staff weapon includes anything with a long wooden haft, so spears, pole arms, flails and battle axes could all be allowed (negotiable). 

There is no reason a Druid couldn't use a firearm, though some will scorn them through affectation or strong belief.

Alignment Restrictions: None - all that True Neutral stuff was propaganda.

Special Abilities.

Richard O'Brien as Gulnar, 'pagan sorcerer'.
Robin of Sherwood (1984-1986).

Altered States: Druids spend a lot of time in Altered States, and not just because it activates or enhances their special abilities - some take them very seriously as sacred rites, others just like to get messy.

If you are in an Altered State, you count a negative Prime Requisite adjustment as positive. Because of this, some Druids will have an incentive to degrade their Prime Requisite, and this is often easier to do than to raise it.

In addition, in an Altered State you can apply your Charisma or Prime Requisite adjustment to Reaction Rolls, whichever is favourable.

I've covered Altered States a bit here, if you don't already have systems in place or want a few ideas.

A simple alternative for the mechanical effects of Altered States would be to roll Dexterity, Initiative and Intelligence at disadvantage (except when it directly relates to using a Druid special ability) or to apply an Initiative penalty like the Mystic class from AD&D 2e Masque of the Red Death. 

The undead, the faerie folk, demons and elementals are probably always in an Altered State by mortal standards. Conjured/summoned monsters, the mentally ill (your group may need to discuss whether this is appropriate), and/or those under a spell can also be considered to be in an Altered State.

Linda Hayden as Angel Blake.
Blood on Satan's Claw/The Satan Skin (1970).

Authority/Influence (Glamour): Analogous to the Cleric special ability, but you can only use it on individuals or those in an Altered State - Druids do not have the awesome centuried might of the Church behind them, but they do possess a mysterious, tangible authority or an oddly compelling manner. It's not far removed from mesmerism, but this is not mind control - they might lose their inhibitions, but they won't lose their will.

You receive no adjustment to the subject's save for your level. However, if your audience is in an Altered State - or you are using this ability to cause/reverse an Altered State in an individual - you can apply your Prime Requisite adjustment.

Three successes in a row on an individual can be used to lessen/remove emotional/mental effects of spell-level equal or lower than that the Druid could cast (in a similar fashion to the Cleric's Casting Out ability.

If both parties are in an Altered State, they do not have to be able to understand each other - the comprehension is not total, but extends to animals and monsters.

Otherwise, the same restrictions apply for the Druid as for the Cleric.

Herne the Hunter - elemental spirit or bloke in a stag's head?
Robin of Sherwood (1984-1986).

Call of the Wild and the Weird: You spend exploding d6 rounds/turns performing a sacred ritual, making loud and varied animal noises, or closing your eyes, spreading your arms and reaching out with your mind. 

You can't do anything else while you're Calling, except for slow movement, cautious or guided. You can Call during combat, but you can't fight while you're doing it.

At the end of this time (it includes narrative/nominal travel time for whatever comes to you), roll 2d6 - you can use your Prime Requisite modifier to either buy down the time or boost the roll. You can keep on trying until you give up or something comes.

On a 9 or better, normal and/or giant animals answer - roll on an appropriate random encounter table. On an 11 or better, your Call attracts supernatural (or otherwise powerful and/or unusual) denizens of the area - random roll or GM choice. Success always Fatigues you.

Spending exploding d6 turns performing the Call improves your respective target numbers to 7 and 9.

If you are in an Altered State, their Reaction is Neutral on arrival.

To try to summon something specific (a wolf or wolves is general; the pack leader/ alpha female/ Ragged General One-Eye is specific) that you know/think dwells hereabouts, your roll is 3d6D1 disadvantage.

You can’t call anything from another plane or from outer space unless you are in a Place of Power associated with it, and there may be specific additional requirements.

Penny Dreadful (2014-2016).

Invisibility to Mortals (Glamour): You must be nude, in an Altered State, in non-magical, non-daylight illumination, and cannot activate this ability if you are under direct observation by anyone who would be affected by it.

You are invisible (actually, automatically camouflaged against your surroundings) to characters of 0 to 2nd level, even if you attack. You are invisible to 3rd level characters, but will become visible to them if you attack them or they manage to hit you. Characters of 4th level and above are unaffected.

Gained at 3rd level, and requires a round of concentration to activate.

Pass Without Trace (Glamour): This is basically the AD&D Druid ability '...to pass through overgrown areas (undergrowth of tangled thorns, briar patches, etc.) without leaving a discernible trail and at normal movement rate.'

However, you get it at 1st level, and you must be nude, in an Altered State, at night. Probably works with dust, sand, snow etc. Those trying to track you might believe you have taken flight as the only explanation.

Recognise Mystery (Second Sight): Similar to the Cleric’s ability to Recognise Evil, but for subtle signs of Old Ways practice, the presence of spirits, places of power, and omens both natural and bizarre. Recognise Evil is more 'know thy enemy'; Recognise Mystery is 'friend or foe?'.

You’re much better at this when you’re in an Altered State, and you can also use your Prime Requisite adjustment to boost the effectiveness of divination (spells or magic items), if such a thing makes sense in context.

Things that might constitute Mysteries: spell-casters, some staple D&D non-human character kindred (duergar, gnomes, elves, half-elves, tieflings, aasimar, genasi), sexuality, gender, kink, secrets, dreams, lies, codes, cant, heredity, pre-scientific science, those under a spell, time travellers, undead, demons, shape-changers, illusions, faerie folk, aliens & alien technology, ancient super-science that seems to be magic, allegorical history/anthropology, arcane and divine language.

Druids also see better in the dark than others, especially in an Altered State. We're not talking full-on dark- or infra-vision here, but definitely at a significant advantage over other human characters.

Spell Casting: You can cast spells from 2nd level onward, using Cleric spell progression. You have automatic access to 1st and 2nd level Druid spells (or Cleric and reversed Cleric spells, if your game doesn't have Druidic magic).

Spells of higher level must absolutely come from (3rd, 4th, 5th) 'supernatural servants of the cleric’s deity' and (6th, 7th) 'direct communication from the deity itself', and should be something of an adventure in itself (1e AD&D DMG).

To cast Magic User spells from scrolls, use Recognise Mystery in an Altered State. I leave it ambiguous whether or not you can do this from 1st level.

You can also learn Magic User spells. Until you reach 9th level, these can only be from a higher level Druid or Magic User (or a monster). Each one blocks out a spell-slot for good – you can only use it for that spell. You are allowed to change or delete a spell when you gain a level. 

What Was Left Out.

The Druid class is meant to encapsulate pagans, witches, mediums, shamans and cultists (groovy and/or Satanic) - it's intended to include the type of character that isn't already a Magic User, but lies outside what is acceptable for the True Faith and Universal Church: elementalists, animists, werewolves (bloodthirsty and/or environmentalist), warlocks, berserkers, dhampirs, emergent psychics (check for psionics or wild talents each level, or when they hit 0 hp and survive), poltergeist girls, firestarters, uptight suburban Satanists, sibyls, practitioners of ceremonial, chaos and/or sex magick, unkillable slashers, seventh offspring of seventh offspring, chosen ones, dryads and hamadryads (if they're not monsters), mystic assassins, changelings, teenagers too deep into The Game of Dungeon or The Game of Vampire, planeswalkers, fairy and witch doctors, uncanny monks, tricksters, occultists, psychonauts (serious and recreational), death metal bards, kings of the wood, defenders of the forest groves, those possessed by devils, even flagellants, heretics and mystics of the True Faith.

There's a lot more I wanted to pack in - some of which can be inferred from the Basic Red Druid - but it was roaming all over the place, so I had to try and tighten things up. 

Anyway, I might revisit in future to cover: Trading Humanity for Power (think Ravenloft and The Blood on Satan's Claw, but not irredeemably evil), Spirit Possession/ Projection (this is where the wildshape special ability goes in my version), Sex and Blood Magick (drawing on the Basic Red Druid), Ceremony/Ritual spell-casting, Cause Mystery (messing with people when you and they are in Altered States).

I've also left out Druid hierarchies and organisations - partly because there isn't an equivalent to the Universal Church for the Old Ways - but I do like the AD&D feature of Druids challenging each other to claim the higher levels, which logically leads to rival covens vying for power while they attempt to defenestrate their own leaders/teachers.

The Hierophant Druid - I know it from 2e AD&D, but I understand it pre-dates that - also didn't make it, though I think there's room if it could be toned down for lower levels.

Commentary.

This is specifically a fictional, pop-culture class - my sources that aren't films, TV or comics (Slaine and Summer Magic from 2000AD) are the (politely) debatable anthropology/history of Margaret Murray's Witch Cult in Western Europe and James Frazer's The Golden Bough, and the religio-magickal traditions of (amongst others) Aleister Crowley, Gerald Gardner and Alex Sanders. 

Some of the Old Ways are not that old at all.

At some point during this process, I looked back on the AD&D Druid with fresh eyes and realised that it's always been a pretty solid Witch class (in the same way as the 2e AD&D Bard is actually a pretty solid Cleric/Priest) - it's just that the medieval environmentalist got in the way.

The original concept was a lot bloodier and sexier, but in the end I cleaved closer to the BOSR Cleric seen in a mirror in a dim room. In much the same way as the Cleric, this class is meant to look villainous from the other side of the hedge - spell-casting as a core special ability for one, rather than an option for the other, is meant to raise the narrative and mechanical stakes between them.

I don't think Clerics and Druids should be able to multi-class with each other, but the idea that the one might abandon all to convert to the other seems narratively interesting.

d100 Mutations

This is something I did a long, long ago - possibly as far back as 1995 (that's the version of Word it says it was made in), certainly 20th Century. 

There's a bit of Commentary at the end.

Just breaking up the text.

Compatible with D&D adjacent systems, but I will have been working with 2e AD&D sources at the time - I've indicated that Initiative and surprise adjustments are for d10, rather than d6.

Roll d100 as many times as you like to see what you end up with. I was presupposing post-apocalyptic humanoids as the base characters, with the idea that they would be wretched outcasts rather than Chaos-gifted superheroes.

01. Abnormally Tall: height is increased by 1-2’, weight by 20-40 lb., and Strength by 1 point. This may change the size category of the mutant for purposes of using weapons and armour. Duplicates are cumulative.

02. Additional Eye: the mutant has an extra eye. Duplicates mean that the mutant has even more; this has no effect on the mutant’s abilities.

03. Adhesive Resin: the mutant exudes a sticky, sour smelling resin from their skin. They can coat themselves in dust, leaves, twigs etc. to achieve a camouflage effect in natural surroundings (e.g. Forest, swamp, desert). The camouflage means that the mutant’s victims are penalised by -4 on their d10 surprise rolls. The mutant cannot use the ability to hide against bare rock or in dungeons. The resin is flammable and the mutant makes all saves vs. fire at a -2 penalty.

04. Albino: the mutant has dead white skin and glowing red eyes. Constitution is reduced by one point. The mutant has a 10% chance of having Light Sensitive Eyes, 25% chance of having Sensitive Eyes and 25% of having Sensitive Skin.

05. Atrophy: One or more parts of the mutant’s body are shrivelled and atrophied. Roll d6 to determine the number: 1-3= 1 part, 4-5= 2 parts, 6= 3 parts. Roll d6 to determine which areas are affected:

1        Head    See Pinhead.
2-4     Arm     Arm useless (randomise weapon or shield arm)
5-6     Leg      One leg: hop at (Mv/3) or ½ with crutch. Both legs: Mv. = 0

Reduce Constitution and Strength, and penalise d10 Initiative rolls by ½ a point for each affected limb: atrophied limbs reduce balance and co-ordination as well as indicating a broader deficiency.

06. Bestial Face: the mutant has a deformed face and head which means that they quite closely resemble an animal type. Their other mutations may heighten this appearance. Typical bestial faces are apes, dogs, sheep, frogs and birds. There is a 50% chance that the mutant is Ugly, 35% chance that they are Very Ugly and 15% chance that they are Extremely Ugly. Duplicates require further ugliness checks (as these are cumulative).

07. Beweaponed Extremities: the hands and fore-arms of the mutant are deformed in such a way as to be similar to blades, stabbing heads or bludgeons. Randomise (d6) for whether damage is piercing, slashing or smashing. Damage is 1-4 plus Strength adjustment per blow. They can only be disarmed in extreme cases (e.g. Severing) but cannot use their hands for anything else.

08. Brightly Patterned Skin: the mutant has brightly-coloured skin, with clashing or contrasting stripes, spots, or other patterns.

09. Camouflage Skin I: the mutant’s skin colour is mottled green, black, brown and grey. In swamp or woodland, the mutant’s victims suffer a -4 penalty to their d10 surprise rolls.

10. Camouflage Skin II: the mutant’s skin is a mottled grey and white colour, allowing it to blend into rock so as to be unseen. Victims are penalised by -4 on their d10 surprise rolls. It only functions against rock.

11. Camouflage Skin III: the skin of the mutant is a slightly translucent black-blue membrane. The mutant can blend into shadows or into the night (even without cover) due to this unusual skin. The mutant’s victims are at -3 on their d10 surprise rolls. There is a 50% chance that the mutant has Sensitive Skin.

12. Camouflage Skin IV: the mutant appears as a featureless black shape, as their skin absorbs all light. They are invisible in darkness and save at +2 vs. light-based attacks.

13. Chameleon Skin: the mutant possesses the ability to shift the colours of their skin so as to blend in with any background. Although it can be used anywhere, it is less reliable than camouflage skins are in their specific areas. The mutant’s victims are at -2 on their d10 surprise rolls.

14. Clear, Slimy Skin Membrane: the skin of the mutant is a transparent, slimy membrane. It must be kept damp (preferably with cool water) or the mutant suffers 1-12 HTC (non-lethal damage) every turn due to the pain of drying out.

15. Cloud of Flies: the mutant is surrounded by a great cloud of swarming flies. In close combat, the mutant’s opponents are at -1 to Hit due to flies getting in their eyes and mouth and crawling up their nose. The mutant may have a glandular mutation causing them to secrete a pheromone that attracts the flies, or they may have very poor hygiene. A third possibility is that the mutant has loose, disgusting skin; the flies live and feed on the semi-liquid mass and maggots can be seen writhing beneath the skin.

16. Cloven Hooves: deformity of the feet and legs means that the mutant has legs resembling those of a goat or similar animal, they may or may not be hairy. The mutant’s movement rate is not affected and they gain a kick attack: this scores 1-2 hits plus the mutant’s Strength bonus.

17. Colour Blind: either the mutant sees everything in black, white and grey or certain colours cannot be distinguished.

18. Diseased: roll d3 to determine how many diseases the mutant is infected with, and then roll on a Diseases Table to determine what diseases they are. Then roll d6  to see what type of carrier the mutant is:

1. The mutant carries dormant diseases and is not immune to them. Each disease will incubate in 1-6 months. The mutant can be cured whenever the presence of a disease is known and healing is available.
2. The mutant is immune to the diseases they carry. These are dormant and do not become infectious for 1-6 months. If the mutant is cured of their disease, they lose their immunity permanently.
3. The mutant is immune to the diseases they carry but they are infectious at present. The mutant retains their resistance permanently.
4. As 2 above, but the mutant retains resistance.
5. The mutant carries no diseases at present but if they are infected they will suffer no ill effects due to their resistance. They will still become carriers. The diseases determined earlier are the only ones they can resist.
6. The mutant is immune to all diseases at all times. However, roll again on this table to determine present condition. A second 6 means the mutant is not presently infected.

19. Disgusting Habit: this causes the mutant to suffer a -2 Charisma penalty. While not strictly a mutation, many mutants act in a way that is repellent to humans and even to each other. Possible habits could include very poor personal hygiene, slobbering, belching or worse (player’s choice). Duplicates are cumulative.

20. Disproportionate Arms: increase Strength by 1 point, but only with respect to the use of hands, arms and shoulders (e.g. Hand weapon attacks, wrestling). In addition, the chance of a successful climbing attempt is increased by 5% (+1 if using a Skill).

21. Dumb: the mutant has some mutation that means they are of low intelligence. Reroll Intelligence and Wisdom using d4 + 4.

22. Dwarf: reduce height by 1-2’, weight by 20-40 lb. and Strength by 1 point. Duplicates are cumulative and this may change the size category of the mutant for weapons and armour.

23. Ear Mutation: roll d6 to determine what unusual shape the mutant’s ears are:

1. Large, pointed.
2. Small, pointed.
3. Large, drooping.
4. Large, fan-like.
5. Huge, humanoid.
6. None (can still hear).

24. Elasticity: the mutant has a rubbery hide and a partially elastic body. This allows the mutant to stretch to twice their height/length or to contract down to half-size.

25. Enormously Fat: for some reason, the mutant is obese in the extreme. This may be due to an enormous appetite, unusual metabolism or glandular mutation. In any case movement is halved, Constitution increases by 1 and the mutant counts as a Large target for weapons. In addition, every time the mutant tries to pass through a normal-sized opening (e.g. a doorway), they will become stuck 50% of the time.

26. Extra Joints: the mutant has extra joints in their limbs. Roll d6:  1-3 Arms. Initiative +1; 4-5 Legs. Movement +1; 6 Arms and Legs. Both bonuses.

27. Extremely Thin: reduce weight by 20-40 lb. and Strength and Constitution by 1 point each. Duplicates are cumulative (unless this would kill the character).

28. Fangs and Teeth: the mutant has unusual teeth or fangs that could be used offensively. The mutant would have to practice with their biting attacks or they would use them as if they were Unskilled with a weapon. Roll d6:

1. Out-thrust tusks. Bite for 2-8.
2. Many small fangs. Bite for 2-8.
3. Long canines. Bite for 1-6.
4. Tushes. Bite for 1-8.
5. Crushing teeth. Bite for 3-6.
6. Saw-toothed. Bite for 1-3 and then 1-4/round thereafter (victim held).

29. Feathered Hide: the mutant has a growth of feathers on their body. This does not affect their Armour Class. This growth may be a downy covering, full feathering with vestigial wings between arm and side or a few wretched patches, as most fingerlings have. Colouring is usually naturalistic unless the mutant has certain other mutations (i.e. Vividly Coloured Skin).

30. Featureless Face: the face and head of the mutant lacks all features, presenting an egg-like surface or one contoured like a normal face. The mutant will usually be deaf, mute and blind, but breathes through their skin or an orifice located elsewhere on the body (the same applies for eating). Some mutants of this sort will have normal senses, others will have alternative ones (such as infravision or a form of sixth sense, maybe equal to the Blind-fighting proficiency).

31. Furry/Hairy: the mutant is covered in heavy growths of fur. Base Armour Class improves by 1 place and the mutant receives a +1 save vs. cold damage.

32. Gills: gills or gill-like growths sprout from the mutants neck or face. Roll d6 to determine their usefulness: 1-4  Vestigial and are of no real use; 5 Can be used to breath water, but must be kept damp or the mutant will suffocate; 6  The gills are as efficient breathing underwater or out of it.

Gills may be slit-like or similar to those of an axolotl.

33. Great Horns: a pair of fine horns grow from the mutant’s head. Unlike the Head Adornment mutation, these horns may be used to make an attack. This attack will score 2-5 hits of butting or goring damage.

34. Growth: the mutant is d3+1 times its normal size and its profile is affected as follows:

• x2        Movement x1.5  STR +2   CON +1   DEX -1   HD +1
• x3        Movement x2     STR +3   CON +2   DEX -3   HD +2
• x4        Movement x2.5  STR +4   CON +3   DEX -5   HD +4

Extra Hit Dice do not affect the Hit Rolls of classed characters.

35. Hand/Extremity Mutations: the mutant has unusual hands that could be used as weapons. Roll d6:

1. Large, thick fingered. Punch for 1 + Str. Bonus. Two hits in a round to strangle: 2-8 + STR bonus/round.
2. Clawed. Claw for 2-5 HTK.
3. Talons. Claw for 1-6 HTK. Cannot use weapons.
4. Pincers. Claw for 1-4 + Str. Bonus. Cannot use weapons.
5. Barbed. Slash for 1 HTK/round and victim is held (Open Doors roll to escape).
6. Knobbed. Blow for 1-3 + Str. Bonus. Cannot use weapons.

36. Head Adornment: roll d6 for the mutant’s unusual head adornment. Spikes and horns cannot be effectively used as weapons by humanoids - the range is the number.

1. None; bald and smooth
2. Mane
3. Frills
4. Lumps
5. Spikes (2-5)
6. Horns (1-4)

37. Heightened Sense of Smell: due to the mutant’s highly acute sense of smell they can distinguish people, creatures and so on by scent (this may take some practice). The mutant gains a +1 bonus to their d10 surprise rolls and it gives a +1 bonus to such non-weapon proficiencies as Blind-fighting and Tracking. There is a 50% chance that the mutant has a Nose Mutation.

38. Hopper: One of the mutant’s legs is huge and powerful while the other(s) wither(s) away. The mutant may only move by hopping. Climbing rolls are penalised by 25%.

39. Huge Head: The mutant has a massive head in proportion to their body. Any Hit Roll of 18-20 will inflict a head injury, such as a blinding or a torn throat.

40. Hunchback: the mutant has a grossly hunched and twisted back. While this looks grotesque, it does not affect the mutant’s profile. Armour and clothing must be specially made.

41. Infravision I: the mutant has infravision to 30’ range. There is a 5% chance that the mutant has Sensitive Eyes.

42. Infravision II: the mutant has infravision to 60’ range. There is a 25% chance that the mutant has Sensitive Eyes.

43. Infravision III: the mutant has infravision to 90’ range. There is a 50% chance that the mutant has Sensitive Eyes and a 25% chance (check first) that the mutant has Light Sensitive Eyes.

44. Invent Your Own.

45. Iron Hard Skin: The mutant has very hard skin, possibly chitinous, warty or scaled. Natural Armour Class is equal to plate mail armour. Any non-magical weapon striking the mutant has a 50% chance of being damaged or broken: it still causes damage on that blow, however.

46. Ironskin: the presence of natural iron or some other metal/mineral deposit in the mutant’s skin means that it has a tougher skin than usual. This gives the mutant an Armour Class bonus of 1. If the mutant also has the Tougher Hide mutation or the Iron Hard Skin mutation they will tend to have very metallic/rock-like skin, possibly restricting their movement.

47. Iron Stomach: an iron stomach allows the mutant to eat bad food, carrion, wood and anything that might be remotely edible with no ill effects. Saving throws vs. Ingested poisons are at +4. Even if a saving throw is not normally possible, the mutant gains a basic saving throw of 16. There is a 50% chance that the mutant has the Disgusting Habit mutation.

48. Keen Hearing: the mutant has an 80% chance to hear noise (as a thief), with a 20% chance in the worst conditions. There is a 50% chance that the mutant also has an Ear Mutation.

49. Lack of a Sense: roll d6 to see which sense is lacking and what effects this has on the mutant:

1. Hearing. Cannot hear. Cannot speak clearly.
2. Sight. Blinded.
3. Sixth Sense. Cannot use ESP, crystal balls, telepathy etc.
4. Smell. Immune to vile odours; -1 to Surprise rolls.
5. Taste. Cannot identify tastes.
6. Touch. DEX drops by 4 points. Cannot find secret doors

50. Light Sensitive Eyes: the eyes of the mutant are very sensitive to light. Normal daylight half-blinds the mutant, who loses infravision (if any) and has their normal vision reduced to 60’. Missile fire is at -8 to Hit and the mutant suffers a -2 penalty to Hit, Armour Class and d10 Initiative. 

It is impossible to pretend not to be painfully affected by the light. It may be possible for light sensitive mutants to slowly adapt to daylight conditions (DM).

For every 4 hours spent in normal daylight, the mutant must save vs. Death ray or be partly blinded: infravision (if any) loses 30’ of its range and normal vision is only 300’.

Light and continual light spells are saved against at -2 and the mutant may be partly blinded (as above) if they are affected, in addition to the usual spell effects. Protect eyes (see below) allow a +4 save vs. the partial blindness and a +2 bonus vs. light spells (the +4 and -2 adjustments are cumulative). 

 Best I could find of the edition I had.

51. Limb Loss: The mutant lacks one or more limbs. Roll d6 to determine which: 1. Both/all arms: No weapon or claw attacks, no shield; 2 Both/all legs: Mv. 0; 3-4 One arm: Randomise between weapon and shield arm; 5-6 One leg: Reduced movement; see Atrophy.

52. Long Legs: the mutant has exceptionally long legs. Increase movement rate by 1.

53. Long Neck: the mutant has an unusually long neck. This has no effect on the mutant’s profile but it should be noted that any Hit Roll of 20 will sever the neck, resulting in a torn throat or decapitation.

54. Mannequin: this is a very unusual mutation, possibly resulting from mutation of unborn twins in a similar way to the Conjoined Twin mutation.

The mutant’s facial features have atrophied until only the mouth is functional. A miniature upper body, complete with head and arms, grows out of the redundant forehead. The mannequin has a separate hit point total to the mutant, equal to 10% of the mutant’s hp. Any head hit (including natural 20s) will damage the mannequin: the mutant cannot survive the destruction of the mannequin.

55. Massive Intellect: the mutant is exceptionally intelligent. Increase Wisdom and Intelligence by 1-4 points, up to a maximum of 20. Mutants with scores of 19 and/or 20 tend to have swollen heads, and a greater likelihood of psionics.

56. Mercreature: the mutant cannot easily move about on land as its legs and arms are so deformed as to resemble flippers (Mv. 1). This does mean, however, that the mutant is a good swimmer (Mv. 12). Mutants with this mutation also tend to have certain others that make them more typical of a mercreature, such as increased lung capacity.

57. Mindleast: the mutant has a score of 1 Intelligence and 0 Wisdom. They are immune to all mental effects and will fight on at negative hp (see Stupid). Mindless mutants will obey their leader/handler without question, and can hardly act on their own at all.

58. Mindless: treat the mutant as feebleminded.

59. Multiple Arms: the mutant has one or more extra arms. Roll d6 to determine how many: 1= one, 2-4= two, 5= three, 6= four. Each extra arm (in theory) allows an extra attack. The mutant can also use an extra shield, to a maximum of two. Increase Strength and Constitution by ½ a point for every extra arm.

60. Multiple Heads: roll d6. On a score of 6 the mutant has two extra heads, otherwise they just have one extra. Increase Constitution by ½ a point per extra head. 

There is a 50% chance that the extra head is near enough useless, maybe twitching or rolling its eyes.

There is a 25% chance that the heads share the same consciousness and all mental attributes: killing one kills them all.

There is a 5% chance that the heads are separate but co-operative entities: increase number of attacks by one per extra head, each has its own Intelligence, Wisdom and Charisma scores, and the mutant may survive the loss of one or more heads (System Shock).

61. Nauseating Oil Secretion: this mutant secretes an oil which produces a stench that nauseates those in combat with it. The opponent(s) must save vs. Poison or suffer a penalty of -2 to Hit while in hand-to-hand combat with the mutant. Certain creatures will be immune to the stink (e.g. Similar mutants, those with no sense of smell, those with Iron Stomachs).

62. Nose Mutation: roll d6 to determine the unusual characteristics of the mutant’s nose:

1. Wide, protruding.
2. Slits only.
3. Hanging Snout.
4. Long, pointed.
5. Large, covered in warts.
6. Narrow, beaked.

63. Overgrown Body Part: one or more parts of the mutant’s body are abnormally large. Roll d3+1 to determine extent of the growth and d10 to determine the parts affected:

All the fractions are half. Those are asterisks at the bottom of the Mv. column.
I snipped rather than try and reformat, which is why it's not great to read.

No ability score may drop below 1. 

* Mutants with a heavily overgrown torso must move on all fours at ¾ their movement rate.

64. Pinhead: the mutant has a small head in relation to the rest of their body. There is a 50% chance that the mutant is Dumb and a 25% chance (check first) that they are Stupid.

65. Player’s Choice.

66. Powerful Legs: the legs of the mutant are strong and suited for jumping. This confers a bonus if the mutant leaps into combat. Roll d6 to determine exact strength: 1-4. 15', +2 to Hit; 5. 30', +4 to Hit; 6. 45', +6 to Hit.

67. Protected Eyes: the mutant has hooded eyes with nictitating membranes. They gain a +4 to any saves that must be made to protect their eyes (e.g. Spitting cobras, corrosive dusts, gaze attacks).

68. Puny: the mutant shrivels to one-quarter of its original weight, and its muscles wither to almost nothing. Strength and Constitution are reduced to one-quarter of their original values, to a minimum of one.

69. Quadruped: the mutant goes on all fours, deformity of the body preventing upright stance. Hands will tend to resemble feet or vice versa. The mutant will find it hard to fight unless they have some other mutation, (such as Fangs and Teeth) as they are poorly equipped to stand up and wield a weapon. Movement rate is not affected.

70. Rearranged Face: extreme deformity means that the mutant’s facial features are rearranged. Possibilities include: mouth and eyes change places; mouth in forehead; whole face upside down; mouth vertical with one eye and one nostril on either side. Check for ugliness as if the mutant had a Bestial Face.

71. Regeneration: the mutant’s body chemistry, metabolism and cell structure allows it to recover from wounds at a faster rate than normal (recover 2-4 hp per day: randomise each day, vary for conditions or randomise a set rate). The mutant can also regrow any lost body parts in 1-6 weeks (again, randomise or vary). However, the mutant cannot regenerate if it is slain as all life functions will cease (thus, most regenerating mutants cannot survive a stab in the heart or decapitation).

72. Rotting Flesh: the mutant’s flesh is rotting and hangs in leprous, stinking fronds. Exposed organs can be seen through rents in the flesh and digits may be missing. The mutant suffers a penalty of 1 point to Strength, Dexterity and Constitution, and is Ugly to Extremely Ugly (randomise), but is otherwise healthy and active.

73. Scaly Skin: the mutant’s skin is tough and scaly like that of a lizard or other reptile. Natural Armour Class is equal to leather armour.

74. Sensitive Eyes: when fighting in normal daylight, the mutant suffers a -1 to Hit penalty due to the sensitivity of their eyes. Duplicates are cumulative.

75. Sensitive Skin: in direct sunlight, those with this mutation suffer 2 HTK per hour from burns.

76. Short Legs: the mutant’s legs are about half the size they would normally be. Movement is halved.

77. Shrink: the mutant is undersized. Roll d6 and consult the following table to determine the extent of shrinkage and the effect on the mutant’s profile. No ability score may be lower than 1.

1-2 half size                     Mv. x2/3        STR x2/3    CON x2/3
3-4 one-third size             Mv. x½          STR x½      CON x½
5-6 one-quarter size         Mv. x1/3        STR x1/3    CON x1/3    -1 hp per HD

78. Conjoined Twin: the mutant is two joined entities. Each has its own profile and canl have different mutations to the other. If either twin is killed, the whole will die. Movement is reduced by half. Roll d6 to determine how the twins are attached:

1-3 Back to back: Mutant cannot be attacked from the rear.
4-6 Side by side: Twins only have same number of arms as the original mutant.

79. Single Eye: the mutant has but a single eye in the middle of their forehead. Due to their poor depth perception they use missile weapons at -2 to Hit. However, they save at +2 against illusions and mirages.

80. Skeletal Face: the mutant has very thin, translucent skin drawn tight over their skull, giving them the appearance of a skull-headed creature. Such mutants may be mistaken for undead and treated accordingly.

81. Skull Deformity: roll d6 and consult the following table to discover what shaped-head the mutant has because of their malformed skull.

1. Wedge-shaped
2. Conical
3. Discoid
4. Spherical
5. Cubed
6. Elongated Skull

There is a 25% chance that the mutant is also Dumb and a 5% chance that the mutant is Stupid.

82. Stinking Musk: the mutant produces a very powerful smelling musk. Those within 10’ must save vs. Poison. Those who succeed must retreat immediately or count as having failed the save. Those who fail retreat and retch with extreme nausea for 1-4 rounds. Certain creatures will be immune to the stink (e.g. Similar mutants, those with no sense of smell, those with Iron Stomachs).

83. Stupid: reroll Intelligence and Wisdom using d4 + 1. The humanoid is also single-mindedly tenacious and can continue to fight if brought down to 0 through to -6 hit points. At -7 hit points or lower, death is immediate.

84. Tail: the mutant has a tail. This has no effect on the mutant’s profile. The tail may be of almost any sort, generally fitting in with the mutant’s other mutations (e.g. A mutant with a Feathered Hide may have a bird-like tail, a Mercreature may have a divided or flattened one).

85. Tarry Slime: a tar-like skin excretion oozes from the mutants skin. There is a 5% (1 in 20) chance that anything striking the mutant or anything the mutant strikes with a tarry appendage will be stuck for part of the round. If the mutant has stuck itself to a victim by its attack, the mutant may make a second attack. If an item has struck the mutant, there is a 25% (5 in 20) chance that the item is pulled from the user’s grasp and the mutant will gain Initiative on the next round.

86. Telescoping Limbs: the mutant is able to extend their arms and/or legs due to mutations of bone and muscle. Roll d6:

1-3 Arms: Can double reach
4-5 Legs: Can add 50% to height
6    Arms and Legs: As above

87. Tentacles: some of the mutant’s arms are tentacles, they may be used as weapons scoring 1-2 hits per blow and may also use various items. However, they cannot be used for tasks requiring fine manipulation, incurring certain penalties to certain actions. Roll d6 to find out how many arms are tentacular: 1-2= 1 arm, 3-5= d3 arms, 6= all arms.

88. Thick Cranium: the mutant with this enlarged forehead can use it as a club in combat (1-4 HTC per blow). Subtract 1 point of Intelligence.

89. Tougher Hide: natural Armour Class improves by 2 places.

90. Transparent Skin: the mutant has completely transparent skin, revealing its inner workings for all to see. This looks somewhat disturbing and bizarre, but does not affect the mutant’s profile.

91. Unusual Eye Colour: roll d6 and consult the following table to determine the mutant’s eye colour:

1. Dull black
2. Purple or Violet
3. Metallic (player’s choice)
4. Maroon or Red
5. Blank white
6. Opalescent

92. Unusual Eye Shape: roll d6 and consult the following table:

1. Huge, protruding
2. Small, stalked
3. Large, turreted
4. Small, sunken
5. Large, round
6. Small, slitted

93. Unusual Skin Colour: the mutant’s whole skin is an unusual colour. Roll d6 and consult the following table:

1. Unearthly Hue (Colour Out of Space, Dolm, Jale, Ulfire, Shining Blood etc.)
2. Blue
3. Orange
4. Green
5. Purple
6. Grey

94. Very Strong: the mutant is fabulously strong. Add d4 points to its Strength score. Such mutants are usually large and well muscled, with bulging torsos and huge crushing hands. If the bonus is 3 or 4, add 1 point to the Constitution score as well.

95. Very Warty Skin: every inch of the mutant’s body is covered in large, ugly warts. The mutant’s natural Armour Class is one place better than normal.

96. Vile Smelling Fatty Secretion: the mutant oozes a fatty excretion all over their body. This has a particularly vile odour and all within 10’ of the mutant must save vs. breath weapon or suffer 2-5 hours of nausea and disorientation. These victims strike at -2 to Hit and -1 to damage. This same secretion protects against natural cold. Certain creatures will be immune to the stink (e.g. Similar mutants, those with no sense of smell, those with iron stomachs).

97. Viscous Black Oil: from its pores the mutant can secrete a viscous, non-flammable black oil. This oil gives the mutant a natural resist fire ability and also allows it to slip out of others’ clutches.

98. Vividly Coloured Skin: the mutant has a skin or pelt that is coloured in some exceptionally vivid shad, such as bright purple, pink, orange or electric blue.

99. Webbed Hands and Feet: webbing grows between the mutant’s fingers and toes. 75% of the time this has no appreciable effect. 25% of the time, this mutation is accompanied by foot and hand deformities that make the mutant an effective swimmer (Mv. 12).

100. Wings: the mutant has a set of vestigial wings on their back, these can be flapped and folded etc. They may be bare, hairy, scaled or feathered. 

Unless combined with other suitable mutations (negotiable), they will not allow a mutant to fly in any way. With the right mutations, though, wing-aided hops/jumps and short-range gliding could be allowed.

And again.

Commentary.

I've done a little cleaning up of the language here and there. I was uncritically using pre-existing material, and 20+ years later, some of it really jumps out at me. 

Unusual Skin Colour has been updated from the original list (I think from 1e AD&D MM2); Mindleast and Conjoined Twin had different names before.

I remember drawing heavily on an article from Dragon about humanoids as PCs, the mutations from Warhammer 40K (a hardback - maybe the 1st edition) and an article in White Dwarf that was the mutations chapter from Realms of Chaos. I couldn't tell you how much I lifted wholesale from these sources, but I can also see mutation mechanics that are lifted directly from AD&D Monster Manual 2 and 2e Monstrous Compendia.

I also recall the influence of Michael Swanwick's In The Drift (1985), Samuel R. Delany's The Jewels of Aptor (1962) and A. A. Attanasio's Radix (1981).

I thought I was working Dark Sun-adjacent, but it turns out that I just never took a proper look at stuff like Gamma World - which I now see was closer to what I was aiming for than a version of D&D.