The Amazing Colossal Man is a 1957 American black-and-white science fiction film directed by Bert I. Gordon starring Glenn Langan, Cathy Downs, and William Hudson. The film is based on the uncredited short story "The Nth Man" by Homer Eon Flint. The story follows U.S. Army Lt. Colonel Glenn Manning, who survives a plutonium explosion during a military test. After the blast, he begins to grow at an alarming rate, reaching heights of up to 60 feet. As he grows, he also loses his sanity, leading to destructive behavior. The film explores the psychological effects of his transformation and the challenges faced by his fiancée, Carol Forrest.