Homer clones himself with a magic hammock; Zombie cowboys come back from the dead after Springfield bans guns; The Simpsons family take a vacation on an island where Dr. Hibbert can turn people into animals.
During World War II a German U-boat is apparently haunted by a repetitive banging on the hull which only occurs when it is submerged. Eventually the noise so frightens the captain and crew that they bring the submarine to the surface and surrender. It would appear to be haunted by the ghost of a worker who died on board during its construction.