In New York, mysterious radioactive ooze has mutated four sewer turtles into talking, upright-walking, crime-fighting ninjas. The intrepid heroes - Michelangelo, Donatello, Raphael and Leonardo - are trained in the Ninjutsu arts by their rat sensei, Splinter. When a villainous rogue ninja, who is a former pupil of Splinter, arrives and spreads lawlessness throughout the city, it's up to the plucky turtles to stop him.

Krang is a fictional supervillain appearing in Teenage Mutant Ninja Turtles-related media, most frequently in the 1987 animated series and its associated merchandise, such as the Teenage Mutant Ninja Turtles Adventures comic book and most of the classic TMNT video games.