A corporeal undead creature resembling a ghoul that subsists by eating the flesh of other undead creatures
The conditions that create a Cadaver are unknown, but it's rumored it arises in areas of dungeons or ruins that have been rich in undead for long periods of time. A cadaver is a corporeal undead creature bearing a physical resemblance to a ghoul. It is not exceptionally smart but shouldn't be underestimated. A cadaver is believed to subsist by eating the flesh of other undead creatures.
Basic Fantasy Field Guide Omnibus