"Polymorph" is the third episode of science fiction sitcom Red Dwarf Series III, and the fifteenth in the series run. It premiered on the British television channel BBC2 on 28 November 1989. It is considered by some to be the series' best. Written by Rob Grant and Doug Naylor, and directed by Ed Bye, the episode has the crew fighting a shapeshifting, emotion-stealing creature. It is the only Red Dwarf episode to feature a pre-credits warning about the content. The episode was re-mastered, along with the rest of the first three series, in 1998.