Intellect Devourer

Abberations, resembling brains with legs, who serve Mindflayers. They are created by the mindflayers in an arcane ritual, involving submerging a brain in vats of magical fluid, although they could also be birthed spontenously by those who had been repeatedly fed upon by other intellect devourers.
As their name suggests, they sustained themselves by consuming the mental energy of sapient beings, until they were left as little more than mindless husks.