The Lonely Mutation Of Baxter Stockman
Teenage Mutant Ninja Turtles (2012 TV Series) episode
Season Code: 216
Episode: 42
Original airdate May 4, 2014
Written by Brandon Auman
Producers: Vladimir Radev
Directed by Sebastian Montes
Voice Direction Andrea Romano
Supervising Director  Ciro Nieli
Episode chronology
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"Mazes & Mutants" "Newtralized!"

Teenage Mutant Ninja Turtles Season 2
October 12, 2013 - September 27, 2014
List of Teenage Mutant Ninja Turtles episodes


  1. The Mutation Situation
  2. Follow The Leader
  3. Invasion of the Squirrelanoids
  4. Mutagen Man Unleashed
  5. Mikey Gets Shellacne
  6. Target: April O'Neil
  7. Slash and Destroy
  8. The Kraang Conspiracy
  9. The Good, The Bad, and Casey Jones
  10. Fungus Humungous
  11. Metalhead Rewired
  12. Of Rats and Men
  13. The Manhattan Project, Part 1
  14. The Manhattan Project, Part 2
  15. Mazes & Mutants
  16. The Lonely Mutation of Baxter Stockman
  17. Newtralized!
  18. The Wrath of Tiger Claw
  19. Pizza Face
  20. The Legend of the Kuro Kabuto
  21. Plan 10
  22. Vengeance is Mine
  23. A Chinatown Ghost Story
  24. Into Dimension X!
  25. The Invasion, Part 1
  26. The Invasion, Part 2

Season 1Season 2 - Season 3Season 4 - Season 5

"The Lonely Mutation of Baxter Stockman" is the sixteenth episode of the second season of the 2012 TV series, and the forty-second episode overall in the series. It first aired was on May 4th, 2014.


Feeling guilty for turning April's father into a mutant bat, the Turtles perfect a retro-mutagen to help him. Unfortunately, things get worse when a newly-mutated Baxter Stockman threatens to mutate April.


Major Characters

Minor Characters


The episode opens in a parking garage, with Baxter Stockman working. However, this is cut short when the Shredder and Rahzar walk in, scolding him for creating these useless mutants, including a duck. Stockman explains that it quacks, flies, and knows taekwondo, but this is obviously not enough to please the Shredder. Stockman then says that he has devised plans for pigs and rhinos, but this still does not get himself off the hook. The Shredder knows that Stockman has failed him one time too many and Rahzar begins approaching the engineer with the intention of severely harming him. But the Shredder has a much more suitable fate in mind - mutating Stockman. The Shredder presses a button on the controller that triggers the bottles on Stockman's neck brace to crack, slowly spewing the contained ooze all over him. The Shredder and Rahzar then leave him behind to mutate.

Meanwhile, at the Lair, Donatello is laying the final touches on the antidote for April's father. April admires his progress, though she starts getting quite tired of observing, and nearly falls asleep. However, after Donnie administers a couple drops of April's unique DNA, the cure is perfected after the mutant cells turn normal. Donnie briefly celebrates, causing all of the other Turtles to enter the room. Donnie explains what type of achievement he has made retro-mutagen, which he made two doses, one for April’s father and one for Splinter. Splinter wonders about being human once more, but he claims he will only take it into consideration once April's father is saved. Leonardo asks Donnie if he could make more of the retro-mutagen, and Donnie replies that 10 canisters of mutagen are usually needed to refine just a droplet of retro-mutagen, but he has no more mutagen left in his lab. On the bright side, they can still look for April's dad and restore him to a normal. April is speechless when she hears this information and kisses Donnie on the cheek, which cause him to pass out.

Meanwhile, in the parking garage, Stockman has transformed into a gigantic fly, due to a fly touching his nose before his mutation. He begins wandering around and stumbling here and there. He spies a nearby chocolate bar on the floor, and devours it with the usage of acidic spit. After this, he ponders over how he is going to become twice the man he once was and figures that if he extracted some DNA from a human being and combined it with his own, he will be himself. He reveals this plan, but Rahzar and some Foot-Bots then show up, wanting to know the outcome of Stockman's ugly mutation. Stockman chooses to hide and snaps several wires in half, which kills all of the lights. Stockman manages to dispatch a Foot-Bot quickly and escapes unnoticed.

Elsewhere, in New York City, Kirby in bat form spies a billboard with a woman pictured on it. He uses his two prominent fangs to bite into her neck, emphasizing his similarities with vampires. The Turtles soon arrive to witness this and converse about not getting Kirby riled up during his capture. April heeds this, and they all approach with relative caution; Donnie prepares a syringe to administer the antidote from behind, but Stockman manages to hear the Turtles and decides that he should take advantage of the situation and squash them like bugs.

Stockman comes into the equation and captures April, holding her tightly in his hands. This distracts the four brothers and clearly gives them away, causing Kirby to fly off into the night sky. The Turtles are stunned to find Stockman in the form of an arthropod, but the engineer then sees the retro-mutagen. He takes an immediate interest in it, though it ends up falling out of Donnie's grasp, and it breaks open when it hits a car down below. Thus, Stockman chooses to abduct April and tells the Turtles to bring more retro-mutagen. He flies off with her back to his lab. The Turtles retreat, and Leo informs Master Splinter of what happened. Splinter approaches Donnie, who apologizes for not being able to change him back to normal. Splinter says that he does not need to be a human, as he is already fortunate enough to live a life with even the slightest bit of humanity. After Splinter tells his son to focus his efforts into the search for Kirby, he contemplates the old picture of his family members. Casey shows up, desiring to beat up someone, and Leo tells him that he & his brothers will need Casey's help to find April. He also tells him that he can use his hockey stick to hit someone (more than once). Raphael and Michelangelo are both responsible for finding Kirby, and Mikey decides to put on his Turflytle Costume, much to Raph's dismay.

Meanwhile, in Stockman's typical lab, he has places April on the ground, and tells her not to move a muscle. April tries to avoid being harmed by telling Baxter that Donnie could synthesize another antidote in a couple hours. However, Stockman refuses, and instead wants to perform a line of risky experiments on April (much like the Kraang). Meanwhile, in a NYC alley, Raph and Mikey are sitting on a ledge of a building, and they spot Kirby in the near distance. Back at Stockman's lab, the villainous engineer ties up April after she tries to attack him with her tessen, and uses rope to suspend her from the ceiling, hanging over the very same vat of mutagen ooze that mutated Dogpound into Rahzar. April says that by mutating her, he will NOT have his wish or former life back, but the troubled arthropod seems to express disagreement. Stockman then renames himself "Stockman-Fly."

Then, Donnie, Leo, and Casey arrive just when Stockman is able to spit a bunch of goo on the rope holding April. They try to be stealthy, but Casey gets distracted by a tiny fly, and kills it, bringing Stockman's attention to Leo, Donnie, and Casey. While the team of heroes engage the wild fly, Donnie manages to step out of the fight for one moment and successfully reaches April's location. However, the rope instantaneously crumbles and April begins to fall into the vat, narrowly missing Donnie's reach.

Everyone pauses in shock and they go to examine the scene. Stockman tries to filly into the mutagen, but Casey knock him out of the way. Leo and Donnie went to see what happen to April, she soon reaches her hands up and emerges out of the mutagen, only to find that she has not changed at all. Donnie then remembers that she is immune to mutagen, and this is what caused her DNA to be so effective in the making of the retro-mutagen as well. The Turtle brothers then make a desperate dash to escape, but Rahzar and his squad of Foot Warriors bust in through one of the brick walls and impede their path forward. Rahzar then takes notice of the glowing, vermilion vial of retro-mutagen and makes a personal resolution to claim it, as he orders his robots to retrieve it to him.

Back outside at the city, Mikey and Raph start flying around with their Turtle Flyers, attracting Kirby's attention (just like in "The Mutation Situation"), and he starts chasing Mikey. He becomes quite frightened when he catches wind of the fact that Kirby is now chasing him. Raph then calls Leo, and sarcastically threatens to allow Mikey to be eaten if Leo does not come to their aid in a short matter of time. Leo then agrees, grabs the vial, and escapes with it, along with his brothers. Stockman is very enraged when he witnesses this and immediately leaves his lab.

Soon, Raph and Mikey land Kirby safely on a rooftop, while April leads the Turtles to their location seemingly by using her mental powers. She approaches her father to talk him down and calm him down. This works and, once again, just as Donnie prepares to give him a sample of the antibody, the canister is snatched from his grasp by Stockman-Fly. Donnie is annoyed of this. Just then, some Foot-Bots with gliders of their own begins to chase Stockman-Fly. The turtles set out to find Stockman, leaving April, Casey and Kirby Bat behind.

Stockman tries to open the canister, but Mikey knocks it off of his hands and Raph catch it. The Foot-Bots appear to chase the turtles all over the city. Stockman manages to get the vial, only to followed by April and Casey riding Kirby. Stockman tries to loose them, but he foolishly collides with a billboard, and the canister is dropped from his hand. The canister shatters, although April has not lost any hope and she pulls the wings back on her father and she makes him go underneath the spilling fiasco, where a drop of the ooze skims his face.

The Turtles then throw a cloth over Kirby and he lands on the ground, reverting back to his normal self. The team celebrates their accomplishment while April is grateful to have her father back. Kirby, who is now human again, is wondering what has happened and why is he naked. Mikey tells Kirby that he will explained the situation later. April is so content for having her father back to normal that she thanks Donnie and kisses him again, causing him to humorously insult Casey by doing a victory dance right in front of his face. Casey gets back at Donnie, however, by tripping him with his hockey stick. Leo notes that Stockman is out of sight, and Mikey begins to run his mouth about Stockman being his 'ultimate enemy'. Raph gets annoyed about this, and tells him to stop saying, "buzz, buzz!!". Mikey agrees, but turns the tables on Raph, by putting his Turflytle antennas on top of Raph's head, and says, "buzz, buzz!". This annoys Raph, and he angrily chases Mikey as he runs off.

Back at the lair, the Turtles stand in their sensei's presence and Donnie says sorry for how he could not turn him back to human. Splinter reiterates that he is fine with being abnormal and that he has adapted to a life that he could not accept as being a part of the human race again. He explains that the lair is his home, and the turtles are his family. Upon hearing these words, the Turtles are fond with sensei's choice.

Meanwhile, the Foot-Bots drag a dazed Stockman all the way back to the Foot headquarters. They then pause and Rahzar approaches. He says that he wants to squish Stockman here and now, but the Shredder has "other plans." The Foot leader then says that Stockman will need to create one last mutant to be evaluated -- and if he messes up, the Shredder will pluck his wings. Knowing that his hateful life will continue from this point, Stockman thanks the Shredder for his 'generosity,' while Rahzar tosses a chocolate bar for Stockman to eat.



The Lonely Mutation of Baxter Stockman/Transcript


  • Stockman held a picture of a mutant called Ace Duck, which was an original character from the 1987 cartoon that started up as an action figure.
  • The chocolate bars that Stockman eats throughout the episode resemble Zag-Nut bars, an actual brand of candy bar.
  • The Turflytle transition is a homage to the Batman TV show transition from the 1960s.
  • Stockman's plan to fuse himself with April to become human is similar to Seth Brundle's plan to turn back to normal in David Cronenberg's The Fly.
  • Stockman says that he is planning on making mutant pigs and rhinos, which foreshadows the appearances of Bebop and Rocksteady.
  • When Mikey was picturing himself as a human, he was shown as Greg Cipes, the voice actor that voices him.
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