My description of a ghoul - 

Ghouls –  Ghouls are very dangerous. They are cannibalistic creatures that feed on the flesh of other creatures, mostly humans. They have a distinctive greenish tinge to their skin and golden glowing eyes. Some ghouls have missing limbs or body parts due to either self-cannibalism or cannibalism of another ghoul. It is not possible to be born a ghoul. One can only become a ghoul through continuous cannibalism affected by dark magic.

Kind of dark, but still pretty cool in my opinion.