The World Tree/Tobarum

Tobarum, abomination of death, is Gagaur's personal pet. He rules over Gehenna where he creates an army of undead creatures, using the souls of the material plane to fuel it. Tobarum creates Gagaur's banshees, ghosts, wraiths, zombies, and other undead creatures. It is said that Tobarum also created the first vampires.