BITTER DRYADS (Brothers/Children of the Pines from the Chronicles of Corum)

The People of the Pines/ Rodney Matthews/ 1977

AC +4 (see below)    HD 4+4 (see below)     Move 100% Normal Human     ML 10 (see below)

Once mortals, the Fomorians poisoned the first with mistleberries and transfused them with the sap of winter pines, making them undead. The Dryads now carry out the ritual themselves, sometimes even persuading the living to join them of their own will - but otherwise by submission.

Bitter Dryads retain their mortal form but skin and hair turns green. Morphic resonance has evergreen leaves and needles, moss, lichens and berry-like growths replace their hair, clothing and personal ornament over time. They bleed green, sticky and slow.

They prefer the shade of the forest, the gloom of winter, and the dark of night, but are not vulnerable to sunlight.

Retaining their intelligence and memories, the Bitter Dryads are the ironic, rustling voice of the  Fomorians in the mortal sphere. They are fully conscious of what they do even as it goes against anything they once loved or believed in their mortal life.

Three blasts of the Horn will strike them as instantly dead as it does the Half-Dead.

The Dryads are inextricably linked (and loyal) to the Fomorians through their weird reptilian steeds.

Dryad Horses are intelligent, capable of subvocal/telepathic communication with their rider and the Fomorians, and serve to direct the Dryads according to that greater will.

It is said that these lizard-things are vomited up by the Fomorians, fully formed extensions of their dire personality.

• As long as a Dryad is in the presence of their Horse, they are an AC +4 HD 4+4 Invulnerable Monster. If they are mounted, they regenerate 1 hp/round - even from 0 hp - and cannot be Turned. 
• Treat mount and rider as a single unit/statblock wherever possible/reasonable.
• A Dryad without a Horse is AC +2 HD 2+2 and normally vulnerable; they also have a -1 Initiative penalty. Morale drops to 8 (or 6 vs. fire). Turned as similar HD undead.
• A Horse without a Dryad is AC +4 HD 2+2, an Invulnerable Monster and regenerates 1 hp/round. Move without a rider is 200% Normal Human, 150% with an unarmoured or shielded rider, 100% with an armoured rider. It is otherwise mechanically the same as a Bitter Dryad.
• No armour benefit unless it is better than their base AC. Shield bonus stacks.
• Can make weapon, missile and unarmed attacks with a Strength of 13 and a Dexterity of 10.
• Immune to cold, gas, hold, charm, sleep and missiles (inc. magic missile).
• Save vs. fire at -2 and take +1 damage per die (ML 8 vs. fire).
• Surprise 1-3 on d6 and undetectable when stationary 1-4 on d6 in evergreen/winter forest.
• At 0 hp, unless by fire or acid, the Dryad is helpless, not killed, and able only to sense and speak. Even beheading and dismembering cannot silence them.
• Dryad Horses try to recover their fallen riders.
• Killing a Dryad's Horse allows the Dryad to be killed with normal damage.

Commentary.

I first encountered the Brothers of the Pine in The Best of White Dwarf Scenarios Vol. II. 

I hadn't read the Chronicles of Corum at this stage, so they were just a cool monster in their own right. 

I remember being fazed by the '-20% Morale' because I thought Morale was on 2d6 not d%, but assumed it was the kind of shorthand that I'd eventually get to understand. At that stage, I thought of rpgs (and rpgs being mainly D&D) in general being a new thing, rather than something that had been around for 10+ years, and expected there to be a lot more compatibility between them than there was.

I've used the BECMI/OSE Wood Golem as the base monster for both mount and rider. 

The relationship of the Pine People to their mounts was something I'd forgotten about, and I couldn't not include it.

THE HALF-DEAD (Ghoolegh from the Chronicles of Corum)

I have a very strong mental image of what the Ghoolegh look like. This is not it, but this is what I could find.

AC as armour     Move 50% Normal Human     HD 5+5 (hp only)     ML 12 (see below)

Balanced on the very edge of death, their blood runs cold and slow and only at the behest of their Fomorian controllers/creators.

They are death pale with bloody red eyes. They are dull-witted, clumsy and sluggish, but capable of operating devices and independently carrying out orders. Their speech is halting and sombre, without emotion. They dimly remember their mortal life and skills.

The Half-Dead act as handlers to packs of Hounds of the Horn (Fomorian hunting dogs) and may be mounted on Ghoul Horses (unarmoured light warhorse, immunity and attacks as a Ghoul and Horse, will not accept rider with more than light armour & shield; carnivorous, intelligent, disloyal and sly).

They must obey whoever blows/holds the Horn of the Hounds, allowing new saves vs. charms etc. If they do not respond promptly to the first two blasts, the third will instantly slay them.

• Always loses Initiative/acts last in a combat round.
• Only defeated when finally cut to pieces or beheaded:
• On critical and/or 9+ damage hits, they lose a limb. On 12+ damage hits, they lose their head.
• Attacks as a Normal Human at -1 to Hit, damage bonus of +2 (or as Strength 16).
• Makes missile attacks as Dexterity 6.
• Can also make unarmed strikes, grapples and overbearing attacks.
• Immune to cold and do not breathe, but are otherwise not undead and can't be Turned.
• The Half Dead are without fear of mortal foe, but fear fire (ML 8), though they can and do use it and are not especially vulnerable to it.
• When the Horn blows once, they panic, struggling to interpret meaning and respond (ML 6).

Commentary.

I'm genuinely surprised that I can't find more gaming material related to The Chronicles of Corum (Michael Moorcock), though that might be because they (especially the more strongly pseudo-Celtic second part) made such an impression on me rather than any wider merit or need.

In an attempt to fill that gap, here's the Ghoolegh (pronounced however you like) in approximately older edition D&D dress-up. I'll follow up with the Hounds of Kerenos, the Brothers/Children of the Pines, and the Fhoi Myore.

I've used Dragonwarriors Zombies converted to D&D adjacent - all those hit points represent how much punishment they can take. In the books, one still slithers on its belly to attack when all the bones in its body are broken.

If you don't like the cop-out of a big sack of abstract hit points, use regular Zombies or even Normal Humans but make them Invulnerable Monsters.

I've seen the suggestion to use the AD&D Juju Zombie, though I don't think it's a good fit.

THE HOUNDS OF THE HORN (Hounds of Kerenos from the Chronicles of Corum)

Jill Thompson (art)/Ray Murtagh (colour)
From the comic adaptation of The Bull and the Spear

AC +4     HD 4+1     Move 125% Normal Human     Morale 10

Dead white hounds, the size of a pony or a small cow. Blood red ears - sometimes tails, paws and bellies, too. Capable of great leaps in the air and running tirelessly over miles of snow-covered terrain.

They obey the Fomorians as much because they recognise their power as because they are bound to the Horn. The Horn calls and controls them, but does not strike them dead.

• Bites for 2d4 damage.
• On a crit or if damage rolled >target HD/level, you're knocked prone (50% drop whatever you're holding)
• If they hit a prone target, they worry for 2d4 hits per round.
• If two Hounds both bite the same target, they try to pull them limb-from-limb for 4d4 hits per round; if damage is 12+, they have pulled off a limb and will release the victim to fight over it.
• If you have 3 HD or less, save vs. fear or flee when attacked by a Hound or Hounds; Morale check to hear their baying in the distance.
• Immune to cold.
• They absolutely obey whoever blows/holds the Horn of the Hounds (overriding any other mental control), but can otherwise be directed by anyone able to handle them successfully.
• For even bigger Hounds, swap d6/d8 HD for a d10 or even a d12. Add one or more d4 to damage or give it a 2d6 bite attack like the Bloodbeast.

Commentary.

White Dwarf no. 18 carries stats for Hounds of Kerenos, pitching them as frosty Hell Hounds - though a Winter Wolf would work just as well.

I've used the BECMI Dire Wolf with a bit of Giant Shrew as the base, but there are various monster hounds and wolves across various games and their editions that would work just as well. 

I think that they're living things rather than magical beasts, which is why I've not given them a breath weapon. They are specifically a reference to the Cwn Annwn, with their white coat and red ears.