Cannibal is based on the true-crime story of Armin Meiwes, the "Rotenburg Cannibal" who posted an online ad searching for someone to volunteer to be mutilated and eaten. Unlikely as it may seem, someone actually replied. The film shows a fictional portrayal of the meeting between the cannibal and his victim/participant, their homosexual relationship, and the eventual mutilation and murder of said victim.

Novella McClure is like most struggling actresses in Los Angeles: she's in her early 30s, her fake name sounded cooler ten years ago, and she hasn't landed a role in three years. To top it all off, she's developed a disturbing habit of eating her own flesh. Novella desperately tries to hide her strange condition from her motherly landlord, Eesha, and somewhat psychopathic best friend, Candice, but her body and mind continue to deteriorate in the depressing world of failed auditions and sketchy night clubs. Can a romantic relationship with her psychiatrist prevent her from self destruction? Or will her fatal habit continue to eat away at her?

Geoff, a man with an unusual compulsion to eat inedible objects, calls on the unorthodox services of backstreet practitioner Doctor Dora in order to cure his ailment.