I, Monster
Season 1, Episode 13
Airdate January 25th, 2013
Writter Jase Ricci
Director Michael Chang
Prev. and Next
It Came From The Depths
New Girl In Town

"I, Monster" is the 13th episode of Season 1 of Teenage Mutant Ninja Turtle. It premiered on January 25th, 2013.

"There is a monster inside us, waiting for HIM to unleash it."

Official Description

The Turtles must battle a new enemy who threatens to take over the city and Splinter's mind.


The episode starts off with Dr. Victor Falco trying his very best to re-create his psychic neuro chemical. He is surrounded by cages that are filled with sewer rats, the only test subjects available to him. The scientific community has already found out about his nefarious intentions surrounding his studies and have shunned him by cutting his funding. The enraged Falco nearly finishes making his serum when a few rats chew through some power lines above him and send the wires flying into beakers full of volatile chemicals. An explosion ignites and causes all of Falco's body to get mutilated. However, the chemical that Falco was working on seeps in through his scars. All of the rats begin to flee the flames, but Falco commands them to help him. All of the rats come running back to him and, after Falco discovers his mental control over the rodents, he calls himself the 'Rat King'.

Meanwhile, in the Sewer Lair, the Turtles are thinking about what techniques they should use to catch Master Splinter off-gaurd in a training session with him. At first, Leo tells Donnie that he should come at Splinter, but Mikey then starts running his mouth and Leo tells him to strike first, much to Mikey's dismay. The Turtles then stand up to face off with their sensei and, one by one, they silently lunge at him, but their attacks are dodged and Splinter easily defeats them. Nearing the end of the match, however, Leo is actually able to use his fist to strike Splinter's face, but hesitates to do anything beyond that and is pinned down by his sensei. Splinter tells Leo that the move he made was a very good one, but his hesitation to do anything else is the thing that got him pinned. Splinter then asks the Turtles if they want a rematch - an offer that they instantly rebuff. After Splinter heads back into his bedroom, the boys declare that, before long, they may not even need Splinter to train them anymore. Splinter hears this declaration from his bedroom, however, and seems to be concerned. Meanwhile, the 'Rat King' has come to realize that the humans in New York have been holding out on the rats for so very long. Because of this, he leads a full-scale attack on the city, vowing to have New York cleansed it of its humanity, reclaimed for the rats, and to have the Turtles eliminated from the picture. An uncountable number of rats begin to invade tons of resturants and even homes, forcing thousands of people to flee the city. The Rat King is able to see the panic amongst the streets through the eyes of every rat. Despite his pleasure, the Rat King concludes that his rats may not be enough to stop the Turtles' interferences forever. He then comments that he has sensed somebody who can; Some one who has great skills as a warrior, and somebody who can serve as his 'eyes' and protector. Meanwhile, Splinter is training privately in the Dojo, but the Rat King breeches his thoughts and tries to make Splinter join his side, causing the sensei to fall to the floor. All of the Turtles come out of their rooms to investigate, only for Splinter tell them that he is fine. April soon calls Donnie (which, of course, causes Mikey and Raph to tease him about it), telling him that she is having a small "pest problem" (literally!!). She has been forced to drop her bags of groceries and climb up a telephone pole to seek refuge from the rat swarms. The Turtles are forced to come to her rescue, even though it's daytime. Once they have grabbed April, they all manage to jump onto the roof of a nearby building just before the rats chew right through the base of the telephone pole they were on!! April begins to wonder about what's happening, and Donnie surmises that the attack is being coordinated by a 'higher intelligence' - some one who is manipulating the minds of the city's rat population. Leo then wonders if Splinter could also be affected.

Meanwhile, Splinter is resting back in the Lair and the Rat King manages to make Splinter fall into a reverie. The villain tries to make Splinter realize that both of them have similarities, such as the loss of their humanity, their mutation, the trauma they've been through, and their inner-rat. However, Splinter doesn't want to unite with him. Soon, the Turtles and April return and they all ask Mikey to poke Splinter with Donnie's Bo. Eventually, Splinter wakes up and tells his sons that the perpetrator of all the chaos is their old enemy, Dr. Falco, and that he won't stop until he has total control of the city...and Splinter's mind. He tells them that he was able to look inside the Rat King's mind and find where his hideout is (beneath Harold Square). Before the Turtles leave the lair to put an end to Falco's mind games, Leo urges Splinter to keep warding off the Rat King's telepathic powers.

The Turtles soon find the abandoned utility junction where the Rat King has set up his base, but are set upon by a gigantic wave of rats and are forced to start running from them. Unfortunately, back in their lair, the Rat King has finally convinced Splinter that the Turtles don't have any need for him and Splinter falls under the villain's control. April then walks into the Dojo, delivering a cup of tea to Splinter. However, Splinter charges at her with a Katana. Just as he is about to harm her severely, he is called to the Rat King's side. Afterward, it's revealed that, luckily, Splinter was only able to cut April's bangs with the sword.

The Turtles soon find the hideout and wonder how they're going to destroy the rats that have followed them there. Leo then notices oil drums near the entrance of the Rat King's hideout and tells Raph to expose the oil by hitting the barrels with Shuriken. After this is done, Leo cuts an electrical wire in half and sends both parts flying into the barrels, causing a small eruption that eliminates the rodents. The Turtles then enter the hideout and Raph is surprised by the look of Falco's 'sad halloween costume'. April then calls Donnie with her T-Phone and tells him that Splinter has left the lair. Donnie wonders where he could've gone, but they then hear their sensei's voice right behind them and are shocked. Leo tells his sensei to snap out of his trance, but Splinter comments that he belongs with his 'brothers' and torments that Leo is wasting his words. The Rat King tells the Turtles about his evil plot before ordering Splinter to demolish his own sons. Leo tries to make his sensei refuse, only for the Rat King to remove the band that he covered his own face with, which reveals his terribly empty eyes. This forces Splinter to keep continuing forward. Leo orders his brothers to take down their own sensei, but they all have their butts easliy whipped. Donnie realizes that Splinter may have taught them everything that they know about Ninjutsu, but he might have been going easy on them for the 15 years they've been around...The brothers try to attack again, but Splinter outwits Mikey, Raph, and Donnie, leaving Leo to reluctantly duel with his sensei, while the Rat King watches with satisfaction. At the end of the duel, Splinter is able to knock the Katanas out of Leo's hands before pointing his own Katana at Leo's forehead. However, Leo pulls out a photograph of Splinter when he was a human, along with his wife and his daughter. Leo shows this to Splinter and then backs this up by referring to his sensei as Hamato Yoshi (his actual, human name) for a change. Leo then tells Donnie and Raph to pin Splinter to the ground. Leo calls him "father" for the first time in a while, and tells him that they need him. For one last time, Falco tells Splinter that his place is with his own kind, but Splinter finally snaps out of his trance after he is about to decapitate Leonardo. Splinter defeats the Rat King with just two fingers and the villain lands upside-down on the floor, where he is carried away by a large wave of rats. Mikey then comments that this is the last they'll see of 'Count-Racula', but his brothers facepalm when they hear this and Mikey sneers that he will be naming the next bad guy.

Later, in the Sewer Lair, Splinter is seen in meditation and Leo comes into the room just to ensure that he is all right. Leo then says that, someday, he may become a greater Martial Artist than Splinter himself. Splinter says that Leo did do well, but he then grabs his son by the wrist and tosses him over his shoulder, remarking that "Everything you know I have shown you, but I have not shown you everything I know". Leo then says that it is great to have his sensei back and Splinter chuckles, ending the episode in a comic style.

Splinter's Wisdom

"Hesitation leads to vulnerability."

Character Debuts




  • "Father, we need you."-Leo


  • The episode title "I, Monster" is the same title for the "Tales of the Teenage Mutant Ninja Turtles" issue and the 2003 TV series episode which introduced the Rat King.


  • When Master Splinter is running towards the Rat King, in the first shot he has Leo's katana in his right hand. But in the next shot his right hand is empty.