First up is the blue leader, Leonardo. Leonardo is the leader of the TMNT and is an honorable ninja. He was chosen as the leader by Splinter and takes great pride in it. He is smart, kind, honorable, and skilled in ninjutsu. He can sometimes become frustrated with his team because they often don't listen to his instructions and prefer to do their own thing. Despite this, Leonardo is proficient with a sword, has strategic planning abilities, and is also friends with the mighty mutants, April O'Neil, Casey Jones, and Karai. Leonardo was the one who ultimately defeated the Shredder and ended the war. He also played a crucial role in defeating the Kraang after they turned Earth into Dimension X. While Leonardo can be strict with his team, he remains a good and noble fighter.

Up next is the hotheaded turtle, Raphael.Raphael is the red ninja who has a bad temper. He often gets annoyed pretty easily, but besides that, Raphael is a strong, stubborn, skilled, hotheaded, and rebellious ninja. He is the muscle of the TMNT team. He does get a bit jealous of Leo becoming the leader and thinks he cando a better job than him. Raphael does have a soft spot for the ones he cares about. Raphael then becomes best friends with Casey Jones, after they had a brief battle with each other. Raphael seems to be the one responsible for Casey when he gets himself into trouble. Raphael knows how to use his weapons, ninjutsu, enhanced strength, and stealth. He is also in a relationship with Mona Lisa, an extraterrestrial salamander that Raphael met. Raphael may not care too much about people, but he is still willing to help his brothers defeat the Shredder.

Now the brains of the group is Donatello. Donatello is intelligent, kind, noble, and sometimes anxious. He is usually the one who has to come up with every solution because of how smart he is. He gets annoyed at that sometimes because it can be too much pressure for him and he doesn't want to be the one responsible for it. He is the smartest of the group, which makes him the most reliable in inventions and gadgets to help in any situation. Donatello knows how to fight with the bo staff, ninjutsu, intelligence, stealth, and agility. He also has a crush on a beautiful girl, April O'Neil.He has been trying to get to her even though April doesn't seem that interested in him. They may be good friends, but I think that would just be it for them.

Next is Michelangelo. He is the youngest turtle of the brothers and is known for being very goofy, silly, rebellious, creative , and kind. He is the most playful ninja of the group. Michelangelo can be resourceful at times when he really needs to be, to save the people he cares about. He can be naive when meeting new people or interacting with those he already knows. Additionally, he can be smart with his photographic memory. For example, when he accidentally bumped into Donnie's shelf and reorganized it without even thinking about it. Michelangelo pays attention to whatever interests him in a cool way but can be reckless with his choices. He is skilled in fighting with nunchucks, ninjutsu, intuition, creativity, and unpredictability. He has a talent for befriending others even when they may not see the good in them. Michelangelo gives everyone a chance and is not afraid to try new things, even though he knows they may not work. While he can be childish at times, he has a big heart and cares deeply for the people and mutants he knows.

Now it is the old rat, Splinter also known as Hamato Yoshi. Splinter is an old mutated rat that live in the sewers with his sons: Leonardo, Raphael, Donatello, and Michelangelo. Splinter is an overprotective, paranoid, wise, strict father, who cares deeply about his kids. While Splinter can be a bit stern about the decisions the turtles make sometimes, it's really for their own good. Splinter doesn't usually go out on adventures with his sons because it's their destiny, not his. He can be a good teacher at times, but he mainly spends most of his time with Leo because he is the leader and wants to teach him everything he knows about leadership. Splinter knows Ninjutsu, wisdom, weaponry, healing, high intuition, and pressure point intuition. Splinter also has a daughter, Karai. Her original name was Miwa, but he was kidnapped by Oroku Saki, also known as the Shredder. Shredder held Splinter's daughter captive for over 15 years, but Karai found out the truth and came to live with her true father. Splinter's rivalry with the Shredder has gone from brothers to archenemies. Throughout the years they have been competing with each other for a while. This all started with a girl, Tang Shen. She was Splinter's girlfriend but was killed by the Shredder by mistake. Splinter may have had a hard past, but he is still focused on the things he cares about in the present.

Next up is Donnie's love interest, April O'Neil. April is a high school teenager who was captured by the Kraang. She possesses psychic powers because her DNA is part Kraang and part human. April is smart, mysterious, and stubborn. She meets Casey Jones after he almost hits her with a hockey puck. The two become friends and later develop a romantic relationship. They get along sometimes, but Casey's recklessness and April's stubbornness sometimes create challenges in their relationship. April was trained by Splinter to become a kunoichi, a female warrior. She also becomes friends with the turtles after they save her from the Kraang and they start hanging out together. Donnie often showers April with gifts and attention because of his strong feelings for her, but April does not feel the same way. She tries to maintain a friendship with Donnie even though he wants more. April is skilled in ninjutsu, psychic powers, weaponry, intelligence, and speed. She is a valuable ally and will continue to help the turtles until Shredder is defeated.

Next up is the vigilante Casey Jones. Casey is reckless, stubborn, and arrogant. He has become friends with the turtles, especially Raph who is his best friend. After they had a fight, they were able to compromise and work together. He has two hockey sticks, a bat, and hockey pucks which he uses as tools to help take down his opponents. Casey can be pretty foolish at times, taking on mutants who are much stronger or bigger than he is. He even went after the Shredder, thinking he could take him down, but he often acts before thinking things through. Casey possesses skills in hockey, strength, speed, and driving. He may be impulsive and foolish, but he means well and will do anything to help his friends.

Now, the main antagonist of the series is the Shredder. Shredder is a dangerous fighter who seeks revenge on Hamato Yoshi/Splinter. He tirelessly attempts to kill Splinter for what he has done to his life. Shredder is highly delusional, aggressive, petty, pretentious, and manipulative, bordering on a psychopathic and emotionless spectrum. He has a right-handed sidekick, Tigerclaw, whom he found after his trip to Japan. Shredder is working on hiring people to help him defeat Splinter and the Turtles. He also captured Splinter's daughter Karai, and raised her as his own. Shredder possesses knowledge of martial arts, immense strength, intelligence, stealth, and acrobatics. He also collaborates with the Kraang to help him achieve his goals by making deals with them. Shredder did accomplish his goal of killing Splinter and achieved a sense of happiness. However, after Splinter's death, he was killed by Leonardo by decapitating his head.