Mad Monster Party is a 1967 stop-motion animated musical comedy film produced by Rankin/Bass Productions for Embassy Pictures.The film stars the voices of Boris Karloff, Phyllis Diller, Allen Swift, and Gale Garnett. It tells the story of a mad scientist who summons all the monsters to his island home to show off the secret of total destruction. The scientist plans to retire as the head of the "Worldwide Organization of Monsters", but who will be his successor? The film was created using Rankin/Bass's "Animagic" stop-motion animation process. Like Rankin/Bass's holiday specials, it has become a cult film.The film is a camp homage to the classic monster movies of the 1930s-1940s. It was one of Karloff's final projects, and his last film in connection to Frankenstein.