I, Monster (2012 TV series episode)

"I, Monster" is the thirteenth episode of the animated series Teenage Mutant Ninja Turtles (2012 TV series). It first aired on January 25, 2013.

Plot Synopsis
The episode starts off with Dr. Victor Falco  trying to re-create his psychic neuro-chemical ending up in a horrible accident, scarring his face. He then discovers his mind control over rats, thanks to his chemical.

Splinter and the Turtles are in a training session and Leo finally manages to punch Splinter in the face, but hesitates and is once again defeated. The boys declare that they may not need Splinter to teach them anymore.

Meanwhile, Falco, know calling himself The Rat King, plots to dominate the city. The rats start to invade the city, causing a huge panic. Rat King decides to try to control Splinter, but Splinter fights back. April calls Donnie telling him that she is having a "pest problem". The turtles come to her rescue and manage to escape rats. They figure that someone or something is controlling every single rat in the city including Splinter which means that Splinter will be the ultimate weapon to destroy them.

Meanwhile, Rat King decides to try to control Splinter, but Splinter fights back. He fights Rat King's power in his mind. Rat King reminds him of his losses, his mutation and his inner rat. But Splinter still refuses to join him. He wakes up and tell the turtles who the perpetrator is and that he will not stop until he has total control of Splinter's mind. He informs them of Rat King's hideout and keeps on fighting Rat King while he still can.

The turtles find the junction and are chased by a wave of rats. Unfortunately, Rat King has finally taken control over Splinter. He attacks April, but in the middle of the scene, is called back to Rat King. The turtles find the hideout but also find Splinter there as well. Rat King orders Splinter to attack but when Leo talks to him, Splinter stops. This causes Rat King to uncover his mask, revealing his everlasting creepy eyes. Leo orders them to take their own sensei down but have their butts easily kicked. Donnie realizes that Splinter may have taught them everything they know about ninjutsu all these years, but he has not taught them everything he knows.

When Leo is at Splinter's hand, he shows him a picture of Splinter when he was human, his wife, and his daughter, along with saying his human name. When the turtles pin Splinter to the ground, Leo calls him "father" for the first time. It seem that Rat King remains in control, but Splinter suddenly snaps out of his trance and attacks Rat King, who then disappears in a swarm of rats.

Later, Splinter is seen in meditation when Leo comes into check on him. He then says that someday he will be a greater martial artist than him. But Splinter strikes him and says "Maybe, but there are some things I know that you don't" ending the episode in a comic style.

Trivia

 * April is shown using a T-Phone like the Turtles in this episode. Her original cell phone (and its first replacement) was destroyed in "Mousers Attack!".
 * This is the third episode where the naginata blade in Donnie's staff appears. The first time was in "I Think His Name is Baxter Stockman", and the second time was in "It Came From The Depths".
 * Mr. Murakami makes a non-speaking cameo during the montage of the rat invasion.
 * This is the first episode where the turtles actually fight Splinter as opposed to training with him in previous episodes.