Splinter is a short, plump mutant rat with grey fur, as well as white fur in his ears, white hair with a section tied into a top bun, white bushy eyebrows and a goatee to compliment. He has golden yellow eyes, a red-pink nose, black whiskers on his cheeks, his arms and legs are pink (with his hands having five fingers instead of the usual four) and a small tear on his right ear.
Splinter, unlike his previous incarnations, is laid-back and very lazy as he often sits in the chair. He is absent-minded and has troubling remembering his sons' names, and even refers to them by their mask colors. He also prompts to stir up mischief and trouble with his sons, including stealing the Turtle Tank in "The Fast and the Furriest". However, he is shown to take action when needed, like in episodes such as "Origami Tsunami" and Mrs. Cuddles".
Despite being a father to his turtle sons, Splinter greatly fears an angry Donatello, who usually punishes him with forced views of educational shows.
Once human and now a mutated rat, Splinter is an eccentric mentor to his turtle sons, training them in the art of ninjutsu. Well, when he's not watching game shows and Lou-Jitsu movie marathons, that is! His tail is a weapon that can take on any TV remote!
- Donatello: One of his sons who he has a love-hate relationship. Has a great fear of angry Donatello due to his method of forcing him to watch educational shows for a certain period of time
- Baron Draxum:
- Meat Sweats:
- Mrs. Cuddles: At first, Splinter was oblivious to what Mrs. Cuddles was doing to his sons and April, but was more focused on his hatred towards her growing television popularity. He then sees her as a threat after messing with his family (and his television schedule), even that Mrs. Cuddles has made a "powerful enemy" in him.
- "I will never marry any of them off." - Mrs. Cuddles
- "Nobody roughs up my family..." - Mrs. Cuddles
- "You have made a powerful enemy, rabbit." - Mrs. Cuddles
- Splinter, in this series, is voiced by Eric Bauza, the voice of Tiger Claw from the 2012 TV series.
- According to an interview, the reason that Splinter looks like he's gained a few pounds is because since there's no Shredder in the new series, Splinter has no exact reason for training the Turtles.
- However, after they learn about threats such as Baron Draxum, he begins training the Turtles more seriously.
- According to Leo, Splinter always falls asleep after eating milk and cake.
- In "The Fast and the Furriest", he refers to Donnie as a monster