Zaat (also known as The Blood Waters of Dr. Z, Hydra (Canadian bootleg title), Attack of the Swamp Creatures (US bootleg title) and Legend of the Zaat Monster (proposed re-release title) is a 1971 American cult movie that gained significant exposure when it was used in an episode of movie-mocking television series Mystery Science Theater 3000 in May 1999.Synopsis
The film begins with Nazi mad scientist Dr. Kurt Leopold in his lab, where he has lived alone for about 20 years (it is revealed later in the film that he graduated cum laude from MIT in 1934). He is contemplating his former colleagues' laughter at his formula, which is described as "ZaAt" (read Z-sub-A, A-sub-T, but which he simply calls "Zaat"). His formula can turn a man into a walking catfish. He injects himself with the serum and emerges from a tank as a giant fish-like creature.