Bastaks constituted a species of non-sentient, carnivorous crustaceans. These creatures dwelled in the depths of Substation Grimdock, a prison moon. They possessed a mesmerizing vocalization that induced a trance-like state upon direct eye contact. Individuals exposed to this call would become immobilized, held captive in a hypnotic daze. Their chitinous exoskeleton rendered them impervious to blasters, however, thermal detonators proved effective in disrupting their composure.