Cadaver is the demon hired by Lord Loss to kidnap Art (Artery in disguise) and bring Kernel Fleck into the Demonata's universe. During his retrieval of Art, Cadaver slaughters a large number of teachers and shoolchildren.
He is described as having a stumpy leathery body, four long arms with hairy fingers, a dark green wolfish head, no mouth (until later in Demon Thief) and long drooping ears.
Cadaver may also have been the demon that killed Emmet Eijit in Slawter.
Cadaver is sacrificed on an ocean liner to open a portal for the Shadow.