Intellect devourer

Intellect devourers resembled walking brains on a set of bestial legs. They were servants of the mind flayers and took over their victims' minds on their behalf.

Ecology
Illithids bred intellect devourers by subjecting the brain of a creature (usually a thrall) to a ritual in which the brain started sprouting legs.

During this process, the newly created aberration passed through a larval form called ustilagor before reaching its final adult form.

Appearances

 * Neverwinter Nights