Creature Catalogue
- Carrion crawler - large worm-like cephalopods that scavenge
- Cave fisher - crab-like monster which hides on ledges and hunts by emitting a long strand of sticky filament to trap prey
- Death Dog - evil two headed dog-like creature, rumored to be a descendant of Cerberus
- Derro - a type of underdark dwarf, former slaves of the Duergar, now liberated but many live in poverty
- Duergar - the Gray Dwarves, found in the Underdark
- Earth elemental - creatures composed purely of matter from the Elemental Plane of Earth
- Ettin - nocturnal, two-headed giant-like creatures
- Firbolg - the smallest of the giant-kind, tending to matters of the forest
- Flumph - Sentient and telepathic aberrations with the appearance similar to giant jellyfish which float through the air
- Galeb duhr - Sentient boulder-like creatures with appendages that act as hands and feet
- Gelatinous cube - a ten-foot cube of transparent gelatinous ooze, which is able to absorb and digest organic matter
- Gnoll - clever, evil hyena-men, often worshipers of the demon lord Yeenoghu
- Grick - body like a giant worm, head like a giant octopus
- Grell - levitating brain creatures with beaks and tentacles
- Hook Horror - aberrations with front limbs with sharp, blade-like hooks
- Intellect devourer - a brain with four legs, can live in mindless victims posing as them, sometimes pets of mind flayers
- Kuo-toa - fish-headed people
- Medusa - body of a woman, snakes for hair, and a gaze which turns others victims to stone
- Mind flayer - highly intelligent humanoid people with squid-like heads who feed on brains and are said to have super-natural mental powers
- Myconid - mushroom people of the Underdark
- Neothelid - great leviathans which grow can from the same tadpoles as Mind flayers if left unattended
- Quaggoth - a wolf-like creature
- Rothe - bovine-like creatures found in the Underdark, communicate by somehow emitting lights
- Shambling Mound - mobile, carnivorous shrubs
- Spectator - a sort of junior Beholder with four eyestalks
- Stone Giant - giants with an ability to sense magic through stone and seem to shape rock to their needs as if it were natural
- Succubus - demons which can shape their appearance and charm their victims
- Svirfneblin - Also known as deep gnomes
- Umber hulk - Great beasts with large mandibles and huge claws, gazing upon them creates confusion in the viewer
- wererat - similar to a werewolf, a therianthropic creature (often human) which can trasform to a rat
- Xorn - strange creatures from Elemental Plane of Earth with three arms, three legs, three eyes, and a mouth atop their head.