Mind flayers, also known as illithids, and sometimes referred to as ghaik by the githyanki, were sadistic aberrations feared by sentient creatures on many worlds across the multiverse due to their powerful psionic abilities. From their twisted lairs deep in the Underdark, these alien entities sought to expand their dominion over all other lifeforms, controlling their minds to use them as obedient thralls. They consumed their victims' very personality by extracting and devouring their brains while they were still alive.