Teenage Mutant Ninja Turtles: The Mega Mutation

Teenage Mutant Ninja Turtles: The Mega Mutation is an American/Japanese animated series inspired by the 2003 and 2012 series, and IDW comics.

Plot
Ninjutsu master Hamato Yoshi (Splinter) is carrying his four pet turtles through the streets of New York City when he encounters members of an alien race called the Braain. During an altercation with these aliens, Hamato and the turtles are exposed to an alien chemical called mutagen and they undergo major physical transformations. Hamato Yoshi becomes a humanoid rat and the turtles become anthropomorphic turtles. Splinter retreats to the New York City sewers, where he raises the four turtles as his sons and imparts to them his knowledge of ninjutsu. Now teenagers, the Turtles venture to the surface for the first time and learn that the Braain is using the mutagen as part of their plan to take over New York City. The Turtles befriend the teenage orphan Casey Jones who is the masked vigilante and the teenage student April O'Neil after she was abducted by the Purple Dragons.

The Turtles also learn that Splinter's long-time enemy Oroku Saki (The Shredder) has ordered his Foot Clan to track down Splinter and his sons, and put an end to their clan.

Teenage Mutant Ninja Turtles

 * Leonardo/"Leo" (voiced by Benjamin Diskin) - A cocky, enthusiastic ninjutsu student, learning how to be an effective leader for his three often unruly brothers. He wears a blue mask and fights with two katana swords called Niten Ryu.
 * Donatello/"Donnie" (voiced by Sam Riegal) - In charge of the design and manufacture of all of the tools and weapons in the Turtles' arsenal, and a gifted hacker.
 * Raphael/"Raph" (voiced by Derek Stephen Prince) -