Nabassu

Nabassus were aggressive demons that were eternally hungry for souls.

Combat
A nabassu's very presence darkened the environment around it. These demons were capable of draining a living creature's life force by merely staring at it, and could devour the soul of any creature within an hour of slaying it. A devoured soul could only be restored by a wish spell.

Society
Nabassus were considered outcasts by other demons, who considered the act of devouring souls abhorrent. They made an active effort to be summoned by mortals, so they might feast on the summoner's soul or trade their cooperation for a steady supply of souls.