Dead End (lost zombie comedy film; 1985)
Dead End is a splatter-horror surreal-slapstick zombie comedy film from 1985. The film was directed by Emerson Bixby and concerns a documentary filmmaker going out to investigate a UFO crash, which leads to a zombie apocalypse. The movie reportedly features real animal blood and guts taken from a local slaughterhouse, which apparently caused one or more crew members to get sick on set.
Bixby has said that his personal copy of the film was lost in 1987, and he has since lost contact with cast and crew members, who may or may not possess their own personal copies. However, there are a couple of reviews on IMDb, implying that the movie was either sold in some form somewhere (which one IMDb user claimed on the forums before they were shut down) or that the people who saw the film were unknowingly friends with people who had worked on the film.