The Teenage Mutant Ninja Turtles (or simply Ninja Turtles) are a fictional team of four anthropomorphic turtles, who were trained by their anthropomorphic rat sensei in the art of Ninjutsu and named after four Renaissance artists. From their home in the storm sewers of New York City, they battle petty criminals, evil megalomaniacs, and alien invaders, all while remaining isolated from society at large.