Kerzit appears as 12+ foot tall bipedal ursine creature. The creature’s head is something like a wolf, with menacing silver eyes and black toothed jaws that drool a grayish fluid. Its body is covered with matted black fur that seethes with vermin. The creature has four arms; the upper arms are long octopus tentacles while the lower are chitinous, multi-jointed, almost insectoid arms with serrated edges. Its feet are like wolf paws, but with polished black talons.
Little is known about Kerzit's origins, except he is a minor demon lord (supposedly created by other, more powerful demon lords) bound to the Tome of the Black Heart. This tome enable its current owner to summon Kerzit, but at the same time, sacrifices must be made to the demon if any of the tome's more powerful spells and rituals are to be accessed. The tome's current owner, Eli Tomorast, while exploring the infamous Maure Castle, set up a cult which worshipped Kerzit, thus ensuring that he has a steady supply of sacrifices to the fiend. Kerzit's temple and fane is located in one of the dungeon levels of the castle itself. It is not known what may happen should the Tome be destroyed, but it is suggested that in such an event, Kerzit will fly into a rage and go on a destructive rampage.