Raphael—also known as Raph—is the hot-headed, aggressive, and tough member of the Teenage Mutant Ninja Turtles, known for his red mask and twin sai weapons. He is often portrayed as the "muscle" of the team, frequently clashing with Leonardo but also showing a softer, protective side, especially towards Michelangelo. His personality is defined by his short temper and love for combat, though he deeply cares for his brothers and master, Splinter. He’s the biggest of the group both in height and muscle, also the oldest brother.

Leonardo—or Leo—is the leader and strategist of the Teenage Mutant Ninja Turtles, known for his discipline, maturity, and skill with twin katanas, wearing a blue bandana. He is named after Leonardo da Vinci and is often portrayed as the most serious of the four but he’s also pretty laid back in a way, teasing his brothers.

Donatello—Donnie, or Don—is the intelligent, purple-bandana-wearing member of the Teenage Mutant Ninja Turtles, known as the team's tech genius, inventor, and hacker who wields a bo staff. He is the "brains" of the group, creating their gadgets, vehicles, and weapons, and is often portrayed as more nerdy and calm, with a strong moral compass and a soft spot for his brothers, especially Michelangelo.

Michelangelo—nicknamed Mikey—is the youngest, most lighthearted, and fun-loving member of the Teenage Mutant Ninja Turtles, known for his love of pizza, skateboarding, and catchphrases like "Cowabunga!". He wears an orange mask and fights with nunchaku, though he sometimes uses other weapons like a kusarigama. Despite his goofy and immature demeanor, he is a skilled ninja with a big heart, often providing comic relief and an optimistic spirit to the team.

Splinter is the wise, rat sensei and adoptive father of the Teenage Mutant Ninja Turtles, training them in ninjutsu. His origin varies by adaptation: in the original comics, he was the pet rat of martial arts master Hamato Yoshi, who was killed by Oroku Saki (Shredder); in many cartoons, he is Hamato Yoshi, mutated into a rat by the same ooze that transformed the turtles. He serves as the Turtles' mentor, guiding them with martial arts skill and wisdom, and is a central figure in the franchise, often in conflict with his nemesis, Shredder.