With his brothers captured by Tokka, Rahzar and the Monster Mutanimals, Donnie figures things can't get much worse. Enter: the Omega Mutant, the greatest monster to never win the Nobel Prize.

The villainous, dog-hating madman known as SCRATCH holds the city's dogs hostage! His only demand? For the Night Ninja to surrender! But Leo, April and the Turtles realize there's more to Scratch than meets the eye.