April O'Neil is a major protagonist in the Teenage Mutant Ninja Turtles comics, published by Archie Comics. She appears as the human ally of the humanoid Ninja Turtles, working alongside with them to underminde the Shredder and his forces. She made her first appearance in the Mirage comic series in 1984 as a computer programmer. She was later portrayed as a strong-willed news reporter in the Turtles' first animated series, as a warrior in the Teenage Mutant Ninja Turtles Adventures comic produced by Archie Comics, and various other personas in different TMNT media. Throught the years, April had a variety of incarnations, and had various portrayals; the most memorable one is the 2003 incarnation of the character, where she appears as a former assistant of Baxter Stockman before her discharge by her employer. Since then, she joined forces with the Turtles, assisting them on their various missions. Contrary to her previous incarnations, April is as a savvy tech on a level close to Donatello, making them fast friends once they become allies, though she appears as a big sister figure towards the recon for most of the part.
The 2003 incarnation of the character also appears in the second Heroes vs. Villains as one of the heroes who contribute their effort to thwart the schemes of the powerful and dangerous criminals, including the Shredder, Cobra Commander, and David Xanatos.