S04E25 - Rebel Without a Fin
Synopsis
(Synopsis credited to Ninjaturtles.com)
Another mad scientist, Dr. Polidorius, creates a half-man half-fish named Ray. The Doctor has Ray plant explosives in certain parts of the sewer so that he can sink the city beneath the ocean. Ray is just one of the first fish-men that Polidorius plans on creating for his underwater city.
April, who is covering another Donald J. Lofty building opening, thinks that she sees one of the Turtles peeking out of a sewer drain and goes down to see them. When she gets another look at the person there, she realizes that it's not the Turtles. While following it, she radios the TMNT to tell them what she saw. While April is talking to them, Ray captures her and brings her to the Doctor's lab. The Turtles rush to her aid when they realize she is in danger. By the time that they get to where she is supposed to be, April is gone. While searching for her, the Turtles meet Ray. A battle ensues, but Ray's arsenal of eel electricty and scorpion fish quills defeats