Hideous necromantic rituals give rise to skavelings, or ghoul bats, monstrosities that are not true ghouls but instead are specifically crafted undead creatures. Their creators are the bloodsucking urdefhans of the Darklands, who create skavelings from giant bats specially raised on diets of toxic fungus and the flesh of ghouls-especially brains harvested from these undead. Upon reaching maturity, these giant bats are ritually slain via the use of cytillesh oil. While this poison simply rots away the flesh of most creatures, one of these specially prepared bats will immediately rise from death as a skaveling after succumbing to its effects.