In Turtles Ninja 2: Out of the Shadows (Teenage Mutant Ninja Turtles: Out of the Shadows), the turtles have their work to protect New York City. On one side they have to face Shredder, a villain who they thought dead, but who is more alive than ever.
Shredder returns with a good plan to finish off the turtles. He has kidnapped the scientific inventor of the potion that transformed the turtles, in order to make him an equal for him.
Using it has made two monsters, one in the shape of a rhinoceros and the other in the form of wild boar. These two mutants will throw them against the turtles, in order to destroy them and be able to do so with New York once and for all.
On the other hand, as the turtles fight against Shredder and his two mutants, they realize that there is a new threat coming from the sky, a threat that they will also have to face.