You will Watch Teenage Mutant Ninja Turtles Season 3 Episode 31 online for free episodes with HQ / high quality. Stream cartoons Teenage Mutant Ninja Turtles 331 Michelangelo’s Birthday It’s Michelangelo’s birthday, but none of his brothers seem to remember, and it frustrates him greatly. Meanwhile, Shredder and Krang discover what is possibly an “anti-mutagen” that, after testing it on three rock soldiers, can undo mutations. Shredder, Bebop and Rocksteady are sent to use it on the Turtles, and our heroes have a few close calls. Moth balls have never been so useful.