Feature-length stop-motion animated comedy featuring the voice talents of Boris Karloff, Allen Swift and Gale Garnett. When Dr Frankenstein (Karloff) decides to retire from the monster-making business, he calls an international roster of monsters to a creepy convention to elect his successor. All of the world's most famous monsters attend including Dracula, Wolfman, the Hunchback of Notre Dame, the Mummy, the Invisible Man, the Werewolf, the Creature, Dr Jekyll and Mr Hyde. But Frankenstein's title is not all that is at stake. The doctor has also discovered the secret of global destruction, which must not fall into the wrong hands...