So my daughter is more of an expert on humor in horror, but several ideas: Have you ever read (or scene the movie) "John Dies at the End"... there are a number of tongue in cheek references, like a ghost lock on a ghost door that can only be opened by the girl with an amputation (thus a "phantom" hand) or the opening scene where a man kills a baddie with an axe, then later breaks the handle (and replaces it), then breaks the head (and replaces it), then the baddie comes as a zombie and says: That's the Axe that killed me... Is he right?

My favorite zombie movies are "Shaun of the Dead", "Fido" (the touching story of a boy and his zombie), and "Warm Bodies" (zombie love story).... all of which are more comedy than horror.