Illithid (Mind Flayer)

The brain-eating psionic aberrations of the Underdark.

Illithids, better known as mind flayers, are monstrous humanoids with psionic powers who live in the damp caverns and cities of the Underdark. They see themselves as the rulers of the multiverse, keep other thinking creatures as thralls and slaves, and feed on their brains.

Quick Facts

Alignment: Almost always Lawful Evil
Franchise: Dungeons & Dragons
Other names: Mind flayer
First major: Eldritch Wizardry (1976)
First minor: The Strategic Review #1 (Spring 1975)
Last major: Phandelver and Below: The Shattered Obelisk (2023)

Facts from the source article.

Background

Gary Gygax created them, taking part of his inspiration from Tim Kirk's cover for Brian Lumley's novel The Burrowers Beneath, which showed only the tentacles of its monsters. They first appeared in TSR's newsletter The Strategic Review #1 in spring 1975, described as super-intelligent, man-shaped creatures with four tentacles around the mouth that reach into a victim's skull and pull out the brain. Their main weapon was the Mind Blast, a wave of psionic force whose effects ran from rage and confusion to insanity, coma or death. Artist Tracy Lesch drew the first picture of them.