The Incredible Mr. Limpet is a 1964 American live-action/animated adventure film from Warner Bros. It is about a man named Henry Limpet who turns into a talking fish resembling a tilefish and helps the U.S. Navy locate and destroy Nazi submarines. Don Knotts plays the title character. The live action was directed by Arthur Lubin, while the animation was directed by Bill Tytla, Robert McKimson, Hawley Pratt, and Gerry Chiniquy. Music includes songs by Sammy Fain, in collaboration with Harold Adamson, including "I Wish I Were a Fish," "Be Careful How You Wish," and "Deep Rapture."
The story begins September 1941 just before the attack on Pearl Harbor. Shy bookkeeper Henry Limpet loves fish with a passion. When his friend George Stickle enlists in the United States Navy, Limpet attempts to enlist as well, but is rejected. Feeling downcast, he wanders down to a pier near Coney Island and accidentally falls into the water. Inexplicably, he finds he has turned into a fish. Since he never resurfaces, his wife, Bessie, and George assume he has drowned.