Dr. Polidorius creates Ray, who possesses several abilities of different marine species. He orders Ray to plant explosives everywhere in the sewers. Polidorius wants to blow them up, so the whole city will sink into the water, thus creating a new Atlantis. April O'Neil, who saw Ray during an report is kidnapped by him and mutated by Polidarius into a fish-woman who is to be Ray's mate.
However, the Turtles comes in, defeat the mad scientist, turn April back to normal and save the city. Ray escapes since he never liked working for his boss. He finds a better life under water, with the other fishes (though Ray frightens them).
- Leonardo (Cam Clarke)
- Donatello (Barry Gordon)
- Michelangelo (Townsend Coleman)
- Raphael (Rob Paulsen)
- Splinter (Peter Renaday)
- April O'Neil (Renae Jacobs)
- Burne Thompson (Pat Fraley)
- Vernon Fenwick (Peter Renaday)
- Donald J. Lofty (Rob Paulsen)
- Dr. Polydorius (Alan Oppenheimer)
- Ray (Pat Fraley)
Home media releases
- Teenage Mutant Ninja Turtles: Rebel Without a Fin
- Teenage Mutant Ninja Turtles Season 4
- Teenage Mutant Ninja Turtles: The Complete Classic Series Collection
- Ray was initially supposed to be the character of Ray Fillet, but creator Ryan Brown, as well as Teenage Mutant Ninja Turtles Adventures writer Stephen Murphy, objected to this character being used as a villain. A fish mutant sharing the name of Ray was conceived in his stead.
- When Leonardo was finished talking to April on the Turtlecom the piece of footage of him, Donatello and Michaelangelo walking through the sewers from "Raphael Knocks 'em Dead" was played, this footage was also seen later in the episode when Leonardo said "Let's fan out and search for her!" when they were scouring the sewers for April just before another piece of footage of the water flowing on the sewer floor from the same episode was seen.