Ghoul

Ghouls are the dead who still cling to the world of the living, unable to move on. They attack humans and then devour them. Many believe this feasting to be a ritual act that allows ghouls to absorb the life energy of their prey, but in fact ghouls attack the living in the hope of using their life energy to revive themselves. The more that a ghoul still desires life, the more ferocious it will be in its hunger, but no matter how many living victims they may claim, it is of course impossible for these ghouls to return from the dead.