That Night, A Forest Grew - d66 Monsters of the Sidhe Dream

A circumstance of para-Moorcockian science-fantasy, rather than a location. 

The subtle dimension allowing the so-called fairy folk to radically change shape and size, demonstrate disproportionate strength and take seven-league steps without suffering the consequences of mundane physics. 

Bypasses rationality, allowing animals to speak, the body to survive dismemberment, and lives to be lived fully between the ticks of a clock. As a hyperspace dimension, it is also a way to other places. 

Most reliably occurs on small islands, along riverbanks, at dawn and dusk, at the crossroads, along the treeline, on the shore, in desert oases, ruins and abandoned facilities, on the old straight track, deep in your cups, on sartain nights of the years, wells and springs, in mines, on train-tracks and at bus-stops, motorway service stations, under-maintained and remote parts of generational colony ships and post-apocalyptic quasi-utopian high-tech mega-bunkers.

Roll d6:

1. Roll d6:

1. Owlboars: Squealing, hooting pack of magical hybrids. A challenging meal, but delicious roasted. Capable of climbing and jumping out of trees. Cough up whole mummified corpses. Filthy and riddled with parasites.
2. Hyacinths: Child-sized with bouncing golden curls, goat eyes, forked tongues. Echo, mimic and ventriloquise to lure you from the path. No language of their own. Possibly telepathic.
3. Ophilines: Languid serpentine cats; wind themselves around branches; cannot constrict but can wrap you up to keep you warm or for auto-bite/claw. Intelligent animals that choose not to talk.
4. Shivery Boys: Blue-skinned and frosty, lost boys left out in the cold. Fairies took them in, then got bored with them. They call themselves Jack or Peter or Robin and are looking for ways back to the mortal world. If not already vampires, they will be once they get back home.
5. Surprise Hunting Boulder (1): Greedy for flesh and blood. Once it has chosen its prey, it can reappear wherever and whenever you aren't looking - including your dreams and understairs cupboard. Moves by rolling and tumbling when under observation, or when it wants to make a lot of ominous approaching noise. Thinks it's a lot more charming than it is.
6. Dire Erudites: Reptilian/dinosaurian druids. More like Hierophant druids than the ones of the mortal sphere.

2. Roll d6:

1. Feliquines: Cat-headed, cat-pawed, cat-tailed, cat-patterned horses; approx. 25% have venomous spines along their flanks. 2 on 2d6 it’s a lone Felicorn (with special abilities and a sought-after alicorn).
2. Corpse Elves: Instinctive glamour to appear as a corpse, often someone you know, making them unnerving interlocutors. Teleport via damaged/dead/dying trees. Meld with living trees to regenerate. Initial Reaction Neutral to Friendly.
3. Mousebear (1): Confused cyclical shape-shifter with a tail attack - damage as dagger for mouse, as polearm for bear, special effects from a monster you’d otherwise not use. Even the bear is afraid of the mouse.
4. Crimson Cattle: Soft red hide thick as plate armour; their meat, milk and blood cure physical, spiritual and societal ills. Glamour makes them seem a blazing, roaring, sun-blotting, town-crushing bovine sky-scape dominating the horizon. Intelligent. Variously capable of speech, spell-casting, prophecy and keeping-their-own-counsel. Have a taste for mortal flesh, but not compulsive gourmands. Horns are magical weapons.
5. Zoogs: Tentacle-faced tree-otters. As likely to track, torture and eat you as to share moonwine and news from beyond the fields you know. Sly, stealthy; pretty much like you’d expect. Implacable foes of the Vroons.
6. Shrill Viridian Things: That haunt bleak rivers. You can hear them from a mile off, but that might be ventriloquism. Maybe cross a Phase Spider with a Quickling for inspiration.

3. Roll d6:

1. Wamps (1-3): Blind, snuffling, mammalian, spider-like profusion of legs. Bat-ears and web-paws bright blood red in contrast to bone white skin and corpse grey fur. Thrive on a diet both ghoulish and vampiric. Mate with and grow/hatch from heads/skulls - detached, dead, whatever.
2. Skandars (Treebeards): Towering, hairy, multiple arms; masters of archery, hammerspace and juggling. Sometimes grow thoughtful and go into an overgrown, Ent-like hibernation.
3. Vroons: Amphibious golden-eyed little octopus folk. Walk upright. Talent for mind- and emotion-affecting magic. Generally benevolent. Sworn enemies of the Zoogs.
4. Sandestins (1-3): Elementals of Primal Chaos, unshackled by Time, hidden from Fate, evading Paradox, circumnavigating Error. Everyone is scared of their open-ended ability to manipulate reality. Comfortingly vulnerable to magical binding and command.
5. Wasp Elves: Aposematic nymphs. You bet they’re going to lay eggs in you. Not hostile, but self-interested and dangerous. Larvae (babies) have ranks of chitinous teeth, which they shed shortly after eating their way out of the host.
6. Piss-a-beds (Gnomes): Natural banded armour and venomous spittle (anaesthetic, anticoagulant, lingeringly diuretic). Pangolin-woodlouse things with a taste for blood. Glamour to look like piglets or great grey grubs.

4. Roll d6:

1. Hairy Nuns: (d6) 1 lascivious lamiae, 2-5 neutral clerics, 6 bloodthirsty Ogres in (magical or unconvincing) disguise. 
2. Tusked Knights: (d6) 1 clumsy buffoons, 2-5 incorrigible but more-or-less honourable duellists and jousters, 6 day-walking Vampire Wereboars. Gorgeously carved wooden plate armour; arrows that sprout into saplings. 1 on d6, they’re mounted on Feliquines.
3. Horned Monks: (d6) 1 satyrs, 2-3 neutral clerics, 4-5 mortal Inquisitors rooting out the devilish and glamour’d to ignore their own horns, 6 bloodthirsty Ogre magi in disguise. 
4. Bastard Uncle Toad (1): Troll/Vodyanoi with aspirations of godhood. Become his cleric (carrying his questionable doctrine abroad) – he grants spells up to 4th level (but you must visit him each time for 3rd-4th level spells), keeps your soul in a crystal pool as security, and calls you back as a zombie if you die in his faith. 
5. Maggot Elves: Magpie-plumaged goblin-harpies that like to eat living brains. Inappropriately friendly and conversational during and immediately after feeding. Can sniff out your dreams and desires, to pick out the most luxurious meals. You can (sort of) survive them eating your brain.
6. Homecomers: Bundles of hair, bone and fingernails, lumps of rocks, rotten stumps, and so on that the fairies leave behind when they steal your babies, but all grown up now and exercising their glamour and right to life. They know they're not people now, but they know who they were before.

5. Roll d6:

1. Janus Elves (1-3): Double-headed psychopomps, precogs and demon-fighters. Numerous Orders and Companies - with elaborate rituals, signature special moves, outlandish weapons, and awesome livery - each made up of no more than three members.
2. Wood Pigs (Gnomes): Armoured moth-bears with powerful climbing, digging, rending claws. Have a taste for gold and other precious metals. Disproportionately tough for their size. Sometimes known as aurumvorax.
3. Grandmother Spider (1): Wizened and kindly (but otherwise trad./RAW) Dark Elf matriarch. Loves all her small and giant charges, in the mundane world or otherwise, and they speak to her, so she knows how many you’ve killed and if you’ve broken any spider laws that you have no chance of knowing in advance. Near to or crouched on top of a cottage-sized obsidian sarcophagus, which can uproot itself like Baba Yaga's chicken-leg hut.
4. Sasquatch (aka Dark Watchers, Owlbears):  Shaggy, Human to Ogre-size darknesses, with three restless white marks (eyespots?) approx. where the heart would be if they are as humanoid as they seem. Presence accompanied by chill, stench, the dampening and disruption of glamour. 
5. Mandragora Mandragon (1): Draconic ceratopsian Dire Erudite and Ogre Mage. The Great Druid to beat to rise to the top of the hierarchy in this continuum (turns Hierophant with good grace if you do). 
6. Sleeping Beauties (1-100): Glamour'd Coffer Corpses.

6. Roll d6:

1. Dark Elves (1-100): Dead white skin, lustrous black hair, blank nacreous eyes. Submerged deep in the Dream, they rarely wake. Bunched close together or standing alone, they sway as if by currents of air and water. Their glamour walks abroad, acting out their dreams and neuroses.
2. Lost Wolves (2-12): Baffled and cautious, the Dream has given them understanding and they would like to get home and go back to being animals, please. 1 on d6 accompanied by a mortal child they are protecting or raising. 1 on d12 this child is a Shivery Boy taking advantage.
3. Light Elves (1-3): Beautiful, noble, radiant. Their backs are always towards you and they are always just out of reach while your eyes are open to see them. Prey on the recently dead, the dying, and dreamers/sleepers. 
4. Mothmen (aka Camazotz): Related/similar to the Sasquatch, but with vast spreading wings and red marks/eyespots. Sandestins fear and hate them. The source of those distant and mysterious whale-songs in the deepest woods.
5. Melancholy Ogres: The Dream changes you, and these anthropophagous brigands feel remorse for their horrible crimes and grisly feedings. Help them back to the mortal world and they will reward you with buried stolen treasures and locations/remains of victims. The Dream fades fast and old urges return.
6. Blood Moon (1): Amorphous, gelatinous, cloud-like; leering aerial-amphibious predator. Frightens your bones to jelly, then sucks them out of your still-screaming body. Can squeeze itself small into a burrow or hollow tree, or spread out over the surface of a pool. Not native; trapped in the Dream, but thriving.

Commentary.

Basic inspiration, Sidhi Dream as featured in Moorcock's Chronicles of Corum colliding with the Lovecraftian Dreamlands.

Pronounce it how you like - it was years before I realised Sidhe didn't rhyme with giddy. But maybe Moorcock's Sidhi does?

Probably also inhabited by variations on the Hjorts, Liimen, Ghayrogs and Metamorphs. Lord Valentine's Castle marked a shift in my mental universe, though it was my springboard into Jack Vance rather than pursuit of Silverberg.

Janus Elves a collision of Majipoorian Su-Suheris and an alien species from The Dead (Pete Milligan and Massimo Belardinelli's 1987 strip for 2000AD).

Elves, Goblins, Trolls, Dwarves, Greys etc are local manifestations of cosmos-/dimension-spanning kindreds you could circuitously eventually identify as Eldar/Eldren - selection/evolution over strange aeons and from settling stranger places.

For existing older-edition supplements that might help with fleshing out encounters and adventures in/adjacent to the Dream: The Nightmare Lands (2e Ravenloft, the eponymous domain), and Blood Spawn (2e Birthright, the Shadow World/ the Seeming). Missed these the first time round. Damn.