Teenage Mutant Ninja Turtles (Known in much of Europe as the Teenage Mutant Hero Turtles) are a fictional team of four turtle mutants, who are trained by their sensei, Master Splinter, in the art of Ninjutsu. From their home in the storm sewers of Manhattan, they battle petty criminals, evil megalomaniacs, and alien invaders, all while remaining isolated from society at large. The characters initially appeared in comic books before being licensed for toys, cartoons and film adaptations. During the peak of its popularity in the late 1980s through early 1990s, the franchise gained considerable worldwide fame and success.

The four turtles are:

• Leonardo (Blue bandana and katana blades) — The courageous leader and devoted student of martial arts. As a strict adherent to Bushido, he has a very strong sense of honor and justice. He wears a blue mask and wields a pair of ninjaken. He is named after Leonardo Da Vinci.
• Raphael (Red bandana and sais) — The team's bad boy, Rafael Soares has an aggressive nature and seldom hesitates to throw the first punch. He is an intense fighter. His personality can be alternately fierce and sarcastic. Still, he is intensely loyal to his brothers and sensei. He is good friends with Casey Jones, after having to meet him one night on patrol and challenging him to a fight.
• Michelangelo (Orange bandana and nunchucks) — The easy-going and free-spirited Mikey provides much of the comic relief. While he loves to relax, this Turtle also has an adventurous and creative side. He wears an orange mask and wields a pair of nunchaku. He is named after Michelangelo Buonarroti.
• Donatello (Purple bandana and bo staff) — The brilliant scientist, inventor, engineer, and technological genius. He is perhaps the least violent Turtle, preferring to use his intellect to solve conflicts. He wears a purple mask and wields the bōstaff. He is named after the sculptor Donatello.