When Alopex was a young human girl in her small village, she and her brother Takeshi, later known as "Tiger Claw", were playing in a playground when they came across a Kraang portal which they decided to enter, believing it to be a magic door. Afterwards, the Kraang mutated and experimented on them. After many months of hardships, they escaped together through a portal back to Earth. Believing that they were monsters now, they fled their home and found refuge in a circus sideshow, but felt their skills were much too valuable for that and eventually became top-level assassins in the criminal underworld, who were notorious and feared. Overtime, Alopex manifested a personal vendetta against Takeshi, blaming him for ruining her life due to her mutation, raising her in the assassin life, and bringing about a yet unnamed fate to their parents. This led her to the point where one day Alopex turned on Takeshi, attempting to kill him, and the two savagely fought in a lethal duel. The fight resulted in Alopex cutting off Tiger Claw's tail with her sword, taking it as a trophy, and escaping, but also being severely wounded in the process. Although she escaped, Tiger Claw initially believed that her wounds would be too grave for her to survive. However, as he learned later on, he was wrong, and she now wears his tail around her waist as a belt, a memento, and trophy to remind her of what he put her through.
Alopex arrives in New York City, speeding through the streets looking for a pair of weapons known as "The Cursed Blades of Vengeance" to finish her duel with Tiger Claw, who somehow knows she is in New York via visions of her running at super speed. Alopex later sped past the Party Wagon, sparking the suspicion of the Leonardo and Michelangelo, who were inside at the time and, initially believing her to be a missile, alerted Raphael and Casey that a "fast moving object" was heading for them. Alopex soon passes them and arrives at the museum that is holding the Cursed Blades. Sneaking inside and taking the blades after the NYPD officer on security duty leaves the room, she is immediately spotted by Raphael and Casey Jones, who have also snuck inside, and Raphael advises her to put the blades back and leave. Alopex instead introduces herself and explains the backstory and curse of the blades.
Uninterested in the story, Casey attempts to attack Alopex, but she uses her speed to taunt him by taking his weapons. Casey, however, manages to take advantage of her gloating and tags her with his taser. Angered, Alopex mercilessly beats Casey, hitting him in the face several times at super speed, finishing by giving him a small cut using the blades, thus cursing him, and kicking him against a wall. Raphael then tries to fight her, but Alopex's speed proves too much for him and she easily throws him against a wall. She then nearly strikes him with the blade as well, but halts when she senses that Tiger Claw is nearby. She quickly speeds outside of the building and confronts him. The two fight, but Bebop and Rocksteady soon arrive and aid Tiger Claw, taking Alopex off guard and giving them the upper hand. But Alopex soon turns the tables and knocks out Bebop and Rocksteady, telling Tiger Claw that she will come back for him before speeding off, passing Donatello and April, who were scanning a section of the city in their Patrol Buggy. Later on, Alopex appears on a rooftop and decides to go after Tiger Claw again.
She speed runs to ground level only to be confronted by the Turtles' team, who demand her to hand over the cursed blades, after being informed by Splinter that the only way to break the curse inflicted on Casey was to use the blades on who inflicted him in the first place, passing the curse back to her. Alopex refuses and attacks the Turtles, easily outmaneuvering all of them, while inadvertently redirecting their weapons to Casey as a result of the curse. She is finally stopped when April uses her telekinesis to lift her up high above ground level. Unable to run, Alopex tells the team that she's on a mission to destroy the one mutant who ruined her life: her brother Tiger Claw. Leonardo tells Alopex that he and his brothers' sensei once told them that revenge only leads to more pain. For a moment, Alopex appeared to contemplate Leonardo's words, before swiftly throwing a kunai at April with her toes, distracting her into letting her down, and then knocks Donatello and Casey out of her way to search for Tiger Claw. Before she leaves, Casey begs her to help him break the curse, but she refuses, saying that the only way to break his curse is to either pass it onto her or destroy the blades, neither of which she was willing to do before getting her revenge on Tiger Claw.
Within seconds, she speed runs directly to the rooftop Tiger Claw is on, ready to begin their duel. Tiger Claw asks her to talk with him before she attacks, but to avail, and Alopex begins her attack. However, the fight quickly proves to be heavily in Tiger Claw's favor, as he is aware of her super speed and set several traps to neutralize her. He soon managed to trap her in a M.O.U.S.E.R.S energy cage and take the Cursed Blades of Vengeance from her, nearly killing (or cursing) her with the blades, but the Turtles, April, and Casey arrive just in time to incapacitate Tiger Claw and save Alopex. After they free Alopex, Leonardo helps her up and says that they saved her and now they need her help to save one of them. Out of gratitude and honor, Alopex reluctantly gives Casey one of the Cursed Blades to destroy.
While Casey attempts to destroy the blade, Alopex teams up with April and the Turtles in an all out fight with Tiger Claw, Bebop, and Rocksteady. With the combined teamwork of April and Alopex, they manage to break one of the cursed blades by April using Tiger Claw's freeze blaster to ice it up, rendering the metal brittle enough to shatter on impact with a building. And after Casey breaks the second one with April freezing it as well, Alopex finally pins down Tiger Claw and prepares to decapitate him with her twin kusarigama, but ultimately decides against it as he is the only family she has left. Tiger Claw sees this as an opportunity to shoot her in the back with his ice pistol, but Alopex, clearly anticipating he would do that, uses her super speed to dodge the blast and slice off Tiger Claw's right arm (the one that was holding the pistol), to the shock of the Turtles team. As Tiger Claw screams in agonizing pain while Bebop and Rocksteady come to his aid, Alopex tells Tiger Claw to always remember that she could have taken his life, before taking to the rooftops of New York City once again.
When she was a girl, Alopex seemed to be in good terms with her brother and enjoyed life, however the moment they got mutated, she and Takeshi had nothing but pain and suffering because the Kraang made experiments on them and after they escaped they had no choice but to abandon everything they once knew.
It is unknown if she liked working at the circus, but it is clear that she had deep regrets when she became an assassin for doing horrible things to good people, presumably including her parents, while Tiger Claw embraced their new ruthless and violent lifestyle, Alopex blamed her brother for forcing her to become like this instead of having a normal life.
At first, she was more than determined to kill Tiger claw no matter what, and she even used the cursed blades of vengeance on Casey to prove her point and refused to remove the curse before killing her brother, but Leo gave her a speech of how revenge is consuming her and destroying everyone around her, with that argument, Alopex realizes that she would be trapped in a endless cycle of pain and she would be no better than Takeshi if she killed him. Just as she had the chance to cut his head off, she warned him that she will spare him in exchange of him quitting his shady business, and just as she gave Takeshi her warning, he took the chance to shoot her in the back but she dodged the bullet and cut his arm, then she told him to never forget that she could have killed him for betraying her trust.
Powers and Abilities
- Superhuman Speed: Alopex's primary and most noticeable skill is the ability to move her body at super speeds. She is able to outrun speeding vehicles, see things on a slow motion-like plane, and catch, redirect, and literally dodge bullets. In her initial appearance, she ran so fast that Leonardo mistook her for a missile when she showed up on the Party Wagon's scanner, and even after she passed him he still couldn't get a good look at who or what she was and could only identify her as a "fast moving object". This speed of motion can be channeled through any singular part of her body as well, including her arms, hands, legs, and feet.
- Superhuman reflexes
- Master Martial Artist
- Sixth Sense: Alopex has been shown to detect when Tiger Claw is near even when he is nowhere in sight or earshot. She can even see brief visions of what he is doing at her current moment.
- Twin Kusarigama
- Cursed Blades of Vengeance (formerly)
Alopex is a slender humanoid mutant fox with cat-like eyes unlike most foxes. Her outfit consists of a purple head bandana with a metal tag on the front, a long, red bandana around her neck, light purple, long-sleeve shirt with net opening and a brown chest-plate over it that extends across her left breast area and large holes on the sleeves, and dark purple pants that also have large holes on the pant leg. Around her waist is Tiger Claw's tail that she wears as a belted trophy.
- Unlike her IDW counterpart, Alopex is not an arctic fox despite her name deriving from the archaic Latin name for that animal (alopex lagopus).