Teenage Mutant Ninja Turtles II: The Secret of the Ooze is a 1991 martial arts superhero film based on the superhero ninja team Teenage Mutant Ninja Turtles. The sequel to Teenage Mutant Ninja Turtles (1990), it is the second theatrical Teenage Mutant Ninja Turtles film and the second installment in the original trilogy. There was also a lot of behind the scenes changes and a shift in tone that helped make Teenage Mutant Ninja Turtles II: The Secret of the Ooze not as much of a success as the first, sitting right at the edge of failure.