Septic Man

Jack (Jason David Brown) is an average sewage worker who has been asked to investigate a water contamination in his hometown that has forced everyone else, including his pregnant wife Shelley (Molly Dunsworth), to evacuate. He decides to investigate the local sewage plant but ends up getting trapped in a septic tank by Lord Auch (Tim Burd) and his brother Giant (Robert Maillet). They refuse to let Jack out despite his pleas and the toxic sewage eventually begins to transform Jack into the hideous mutant Septic Man.