His name is Leonardo, though he is called Leo He is a turtle that was exposed to a substance known as "Mutagen"—which transforms bodies and organisms into other forms—turning him into a turtle that acts and speaks like a human. He is part of a team of turtles alongside his three brothers: Donatello, Raphael, and Michelangelo. He is the leader of the Turtle team and wears a blue eye mask; his weapons are twin katanas. He is intelligent, decisive, and possesses strong leadership qualities, and he enjoys comic books and television shows.

His name is Donatello—or "Donnie" for short—and he is a genius when it comes to machinery, technology, and repairs. He is a turtle who was exposed to a substance called "Mutagen" (which transforms bodies and organisms into other forms); this turned him into a turtle that acts and speaks like a human. He is part of a team of turtles alongside his three brothers: Leonardo, Raphael, and Michelangelo. He studies Krang technology and their language, and his weapon is a Bõ Staff.

His name is Raphael—often called "Raph"—and he has a fiery, quick-tempered, and stubborn personality; he also likes to tease Michelangelo. He is a turtle who was exposed to a substance called "Mutagen" (a substance that transforms bodies and living organisms into other forms), turning him into a turtle that acts and speaks like a human. He is a member of a team of turtles that also includes his three brothers: Leonardo, Donatello, and Michelangelo. His weapon is the Sai.

His name is Michelangelo—though he is called Mikey—and he has a fun-loving, lighthearted, and sarcastic personality; he enjoys having fun, skateboarding, and playing video games, and he is afraid of Raphael. He is a turtle who was exposed to a substance called "Mutagen" (a substance that transforms bodies and living organisms into other forms), turning him into a turtle that acts and speaks like a human. He is a member of a team of turtles that also includes his three brothers: Leonardo, Donatello, and Raphael. His weapon is the Nunchaku.

Master Splinter is the one who trained and raised the team of turtles, and he is considered their father. He was exposed to Mutagen, which transformed him into a rat, yet he retained his wisdom and human-like traits; he assists the turtles in their mission to eliminate the Kraang and defeat Shredder and the Foot Clan.

Koray is Shredder's non-biological daughter. A powerful and skilled ninja warrior and a prominent member of the Foot Clan. She is intelligent, quick-witted, and highly confident in her abilities. Initially, she acts as an adversary to the Turtles, carrying out Shredder's orders. Over time, however, she begins to question Shredder and realizes that her loyalty to him is not necessarily justified.

April O'Neil is an intelligent journalist and often the first human friend close to the Turtles. She serves as a link between the Turtles and the human world, aiding them with information and investigations. Brave and inquisitive, she loves uncovering secrets and solving crimes; she is loyal to the Turtles, treating them like family, and often helps them despite the danger. Her father was abducted by the Kraang, and she has known nothing about him since that moment; she begins helping the Turtles, and her power is telekinesis.

The truncated tortoise is the arch-nemesis and leader of the Foot clan. A formidable ninja warrior, his goal is to eliminate Splinter and the Turtles. He wants to take over New York and expand the Foot Clan's influence. Brave and mischievous, he is however sometimes driven by vengeance and hatred. He is Koray's father and is also pursuing the Krang.

A fighter and ally to the Turtles: He assists them in battling criminal gangs and villains, particularly the Foot Clan and Shredder. Fighting style: He uses sports equipment as weapons, such as hockey sticks, baseball bats, golf clubs, and more. Personality: Reckless, hot-headed, and brave, with a strong sense of justice. Relationship with the Turtles: He sometimes starts out as an independent operator doing things his own way, but eventually becomes a close ally and friend.