When four pet turtles were exposed to alien slime, they began to transform and became the Teenage Mutant Ninja Turtles. Raised in the sewers of New York by their adoptive father and wise sensei, Master Splinter, Leonardo, Michelangelo, Donatello, and Raphael fight against crime. Led by Master Splinter, the four turtles learn the ancient martial art of Ninjitsu, mastering skills in stealth, weaponry, and combat. They stop villains in all forms, whether they are barbaric gangs, low-life crooks, disturbed cyborgs, or even the criminal syndicate The Foot, led by their arch-nemesis, The Shredder.