Teenage Mutant Ninja Turtles (1987): Season 4, Episode 36

4 - 36: Beyond the Donatello Nebula

While trying to contact the Turtle Nebula, Donatello meets an intelligent lizard alien named Algernon ("Algae" for short), who must help him and the other Turtles rescue April from a greedy man named Hostile Hiram Grelch.