Leo and Donnie disagree about their plan to stop the Kraang invasion. When Leo makes a critical mistake, he is separated from the team and Donnie must step up as a leader ...

Leo stages a rescue for Karai against Splinter's wishes. ...

When Raph accidentally damages a Kraang machine, it allows him to switch brains with a Kraang. Now he must find a way to convince his brothers and Splinter that it's real ...

When Tiger Claw returns, he vows to hunt and destroy the turtles. Meanwhile, Karai finds out the truth about her mother and real father, forcing her to make a life changi ...

The Turtles create a retro-mutagen to help April's father;Stockman-Fly kidnaps April. ...

When the Turtles play a fantasy LARP game to get their mind off of things, they must separate the difference between fantasy and reality. ...

Leonardo considers asking Splinter for help while facing Shredder's new assassin; Donnie must put aside his rivalry with Casey in order to uncover a Kraang plot. ...

The Rat King returns and tries to take control of Splinter again. Meanwhile, April leaves a cat with Mikey and he turns it into a mutant. ...

When Donnie upgrades Metalhead's artificial intelligence, he must decide if he can trust a sentient Metalhead... or if he has created a new foe. ...

A fungus mutant spreading through the sewers causes the Turtles and April to experience their worst fears as Leonardo must face his greatest fear--losing his team. ...

After encountering mutants and ninjas, Casey Jones decides to take on pure evil alone. When he meets Raphael, the two hot-headed fighters must put their dislike for each ...

The Turtles find themselves being hunted by a new threat--another mutant turtle called Slash, who has a personal vendetta against the brothers. ...

April tries to resume a normal teenage life, but when Karai starts hunting her again, April realizes she may have put her new friend Casey Jones in danger as well. ...

Michelangelo is tired of being the runt of the litter. But when he fools around with some mutagen, he gets a dangerous infection that is mutating out of control. ...

Donatello obsessively experiments with mutagen in a bid to find a cure for April's mutated father. Unfortunately this puts April in danger from a new threat--Mutagen Man! ...

When the Turtles face Shredder's newest threat, an army of Robot Foot Soldiers, Karai captures Leonardo and forces him to do battle with these new and improved ninjas tha ...

While tracking mutagen, the Turtles bring a mutated squirrel back to the lair. When it starts multiplying, the Turtles must hunt the squirrel mutants and prevent them esc ...

When Shredder teams with the Kraang to receive a batch of mutagen, the Turtles' problems only get worse--even putting their friendship with April at stake. ...

As the Turtles make a desperate assault on TCRI to shut down an alien portal, they find themselves engaging in the most difficult battle yet. ...

As the Turtles make a desperate assault on TCRI to shut down an alien portal, they find themselves engaging in the most difficult battle yet. ...

Donatello breaks into a secret Kraang detention center in order to rescue Kirby O'Neil. But when he discovers they are trapped inside with a deadly mutant prisoner, he re ...

When Shredder schemes to create a fearsome army of mutants, the Turtles have no choice but to rely on the help of the newest recruit to the Foot Clan: The Pulverizer! ...

While the Turtles are infiltrating an undersea Kraang base, the Foot Clan attempts to capture April, forcing her to fend for herself in a battle of wits against Karai. ...

After witnessing the Kraang in action, Karai realizes the seriousness of the alien threat and approaches the Turtles to propose an alliance. ...

Fed up with being humiliated by Fishface and Dogpound and defeated by the Turtles, Baxter Stockman seeks revenge by luring both parties into a deadly labyrinth. ...

While breaking into the hostile environment of TCRI headquarters, the Turtles discover the true intent of the Kraang and resolve to stop the alien invasion once and for a ...

The Turtles meet their first fanboy when a teenage wannabe hero decides to fight crime and dress up as The Pulverizer. ...

The Turtles get their first taste of high school when April's school project draws Kraang attention. ...

Leonardo, tired of Raphael's constant criticism, lets his brother try his hand at leadership for a while. Meanwhile, Leonardo meets a beautiful and dangerous female ninja ...

The Turtles must face off against a new enemy, The Rat King, who threatens not only to take control of the city, but Splinter's mind as well. ...

Michelangelo befriends an unstable mutant alligator who possesses a strange piece of Kraang technology, but the other Turtles aren't sure whether Leatherhead is a friend ...

When simultaneous threats from the Purple Dragons and Baxter Stockman's mechanical Mousers force the Turtles to split into two groups, Donnie and Mikey must prove that th ...