Teenage Mutant Ninja Turtles: Fighters in a Half-Shell is an upcoming animated series loosely based on the ongoing Nickelodeon animated television series of the same name, although it borrows some elements from the IDW Comics. The genre is planned to be action/adventure, science fantasy, teen drama, comedy-drama, and dark fantasy. The series has many influences from the ongoing Nickelodeon TV show, TMNT (2012), the previous 4Kids TV show, TMNT (2003), the 2005 TV series, Ben 10 and the 2010 TV series, Young Justice. In addition to two IDW characters (Bludgeon and Herman), Fighters in a Half-Shell also showcases a new character, the elderly mutant tortoise, Master Galapagos.
When four pet turtles were exposed to the alien mutagen, they began to mutate and became the Teenage Mutant Ninja Turtles. Raised in New York City sewers by their adoptive father and sensei Hamato Yoshi aka Master Splinter, Leonardo, Raphael, Michelangelo and Donatello become the heroes they are destined to be. And they're doing all that while trying to defeat Master Shredder, an old enemy of Splinter who is training a peculiar band of ninjas while hiding in New York City. When they are in the surface world, the Turtles become involved in a conspiracy involving alien creatures, robotic droids, monstrous mutants, brutal street punks, and missing scientists. And they come face to face with the alien mutagen that originally mutated them.
The Hamato Clan
- Teenage Mutant Ninja Turtles - A team of anthropomorphic humanoid mutant red-eared slider turtles who are kept a secret from the world by usually going to the surface only in the night time.
- Leonardo/Leo (voiced by Seth Green) - The "leader" of the team. Leo is the take-charge perfectionist who aspires to be a brave, decisive, perfect hero. Unfortunately, he's an inexperienced teen (for the moment at least) with three smart-aleck brothers. He is calm and enthusiastic, and identifies deeply with his ninja lifestyle. He wears a blue mask and fights with two katana swords. He developed a crush on Miwa/Karai/Kiba.
- Raphael/Raph (voiced by Nolan North) - The "hothead" of the team. Hot (in three ways)-tempered and stubborn, Raph is aggressive and struggles with following orders. His deep-seated fear of being alone is masked by his fierce independence and tough-guy exterior. He wears a red mask and fights with twin sai.
- Michelangelo/Mikey (voiced by Greg Cipes) - The easy going, laid-back and positive party dude. He loves comic books, skateboarding, sewer-surfing, playing video games and listening to some EDM. He is the first of the turtles to taste pizza and is very proud of his talent for naming things. He wears an orange mask and fights with two nunchucks. He uses both of his catchphrases, "Cowabunga" and "Booyakasha" in the series. Mikey also has a crush on April's friend, Irma, who does return the romantic feelings.
- Donatello/Donnie (voiced by Jack McBrayer) - The scientist and brains on the team. He is the least violent, but is more than willing to defend his brothers and friends. He wears a purple mask and wields a Bo staff.
- Hamato Yoshi/Splinter (voiced by Hoon Lee) - The adoptive father, trainer and sensei of the Ninja Turtles and the biological father of Miwa/Karai/Kiba. He is wise, mature and highly trained in the art of Ninjutsu. He is the adoptive grandson and student of Master Galapagos.
- Grand Master Galapagos (voiced by Randall Duk Kim) - The adoptive grandfather and sensei of Hamato Yoshi/Splinter and the adoptive great-grandfather of the Ninja Turtles and Miwa/Karai/Kiba. What used to be an ancient ninjutsu master, as he is currently a wiser tortoise-mutant. Highly venerated for his wisdom, knowledge and experience, Galapagos was considered to be a sage. It is also apparent that he seemed to be reckoned as a god in the art of ninjutsu, as he was greatly respected by Splinter, the Ninja Turtles, April, Casey, Leatherhead, Kiba, Slash, the entire Hamato Clan, and the entire universe. His character is inspired by Master Oogway from the Kung Fu Panda film franchise.
- Miwa/Karai/Kiba (voiced by Kelly Hu)
- April O'Neil (voiced by Mae Whitman)
- Casey Jones (voiced by Scott Menville)
- Leatherhead (voiced by Peter Lurie)
- Irma Langinstein (voiced by Tara Strong)
- Spike/Slash (voiced by Corey Feldman)
- Mondo Gecko (voiced by Robbie Fist)
- Herman the Hermit Crab (voiced by Jim Cummings)
- Jack Finney/Ray Fillet (voiced by Jason Biggs)
- Pigeon Pete (voiced by A.J. Buckley)
- Metalhead (voiced by Scott Adsit) - A durable turtle robot created by Donatello.
- Zog (voiced by Dave Fennoy) - A Triceraton mercenary who is the ally of the Ninja Turtles.
- Foot Clan
- Oroku Saki/Shredder (voiced by Kevin Michael Richardson)
- Hunter Mason/Hun (voiced by Kevin Michael Richardson)
- Purple Dragons (various voices)
- Bebop (voiced by J.B. Smoove)
- Rocksteady (voiced by John DiMaggio)
- Baxter Stockman/Stockman Fly (voiced by Phil LaMarr)
- Tiger Claw (voiced by Eric Bauza)
- Bludgeon (voiced by Wade Williams)
- Foot Bots
- Foot Technicians (various voices)
- The Kraang (voiced by Nolan North) - An unknown, Dalek/squid-like alien race from Dimension X.
- Krang the Oligarch (voiced by Steven Blum)