After the Turtles find Bigfoot in the woods, Donnie befriends it and insists they save it from a hunter.
The team discover a Kraang ship buried under April's house, they also uncover April's lost mother.
After he becomes upset, Mikey leaves and befriends a mutant frog he finds in the woods.
Creatures that feed off dreams trap the Turtles inside their own dreams as April and Casey must find a way to wake them up.
When Casey, Raph, Mikey and Donnie are captured by a new mutant, both April and Leo must overcome disabilities in order to save them.
Leo takes the Turtles to train in the woods in an advanced ninja ritual; the Turtles must overcome their weaknesses and face their enemies to become a true ninja.
Donnie finishes a new batch of retro-mutagen in hopes of saving Karai; the Turtles are hunted by Shredder's new henchmen, Bebop and Rocksteady.
Leo is suspicious when Slash emerges leading a team called the Mighty Mutanimals; the Turtles must brave the bizarre world of Dimension X to save the enslaved people of New York.
Casey Jones thinks he can take on the criminal underworld on his own, but soon discovers that he is in over his head.