The classic Dungeons & Dragons mind flayer (illithid) was created by game designer Gary Gygax for early D&D in the mid‑1970s.

Original creator

  • Mind flayers first appeared in TSR’s in‑house magazine The Strategic Review #1 in Spring 1975, described as a super‑intelligent, tentacled, brain‑eating humanoid.
  • Sources note that Gygax devised the monster for D&D and has said he was inspired in part by the cover art of Brian Lumley’s novel The Burrowers Beneath.

In‑world origin (lore)

  • D&D lore later expanded mind flayers into an ancient psionic race that once ruled vast empires and now dwell in colonies ruled by an elder brain.
  • Different editions hint at varying origins, including time‑traveling survivors of a future universe and beings connected to the alien Far Realm, leaving their precise fictional origin deliberately unsettling and mysterious.

TL;DR: In real‑world terms, Gary Gygax created the Dungeons & Dragons mind flayer; in‑universe, their origins shift between “future empire,” Far Realm aberrations, and other eldritch explanations depending on the edition and setting.

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