Harley Quinn has no superpowers, and relies on her unpredictability, gymnastics skills, and weapons and hand-to-hand proficiency. She is a peak athlete, having won a gymnastics scholarship at Gotham City's Gotham State University. Following her transition to main DC canon in 1999, Harley Quinn was established as having immunity to toxins and enhanced strength, agility, durability, and reflexes, which she received after having been injected a serum concocted by Poison Ivy. "Vengeance Unlimited, Part Five" (Harley Quinn vol. 1 #30
) revealed that it also gave her the ability to breathe underwater.
Harley Quinn is skilled in using various weapons, often employing weaponized clown-themed gag items, including pop guns, rubber chickens, and a gun that shoots a boxing glove, as well as oversized pistols and mallets, the latter being her signature weapon. Other weapons she uses include: unconventional weapons, such as a baseball bat; explosive weapons such as bazookas, customized bombs, and dynamites; firearms, such as pistols, assault rifles, and machine guns; Harley Quinn also has a pair of pet hyenas, Bud and Lou, which she can order to attack her opponents.
Despite being mentally unstable and sometimes distracted, Harley is highly intelligent. Her intellect extends to her psychological, tactical and deception abilities, Harleen Quinzel earned a bachelor's degree in psychology and as a former Arkham psychiatrist, was highly qualified in psychoanalysis, criminology, and forensic psychiatry. She is still an expert tactician, deceiver and escapologist, and still shows traces of her psychological experience. Harley Quinn is also shown to have reverse-engineered venom formulas and developed antitoxins. She also has an indomitable pathological will.
Just like Poison Ivy, sometimes and not as much, Harley uses her feminine charm to attract men but only to be able to manipulate them. Unlike her former partner, The Joker, she is able to simulate sanity, thus being able to pretend to be a "normal" person. In this way, she disguised herself as a security guard, a lawyer and even Poison Ivy and Batgirl.
Following her introduction to the DC Universe in 1999, Harley Quinn was depicted as a frequent accomplice and lover of the Joker as well as the best friend of fellow supervillain Poison Ivy. Later stories depicted Quinn as a supervillain who has left her abusive relationship with the Joker behind, beginning with the publication of her first ongoing series written by Karl Kesel in 2000. After years of scarce appearances in comics, Quinn returned in a leading role in 2009 with the Gotham City Sirens series, as part of an unstable alliance with Poison Ivy and Catwoman. In 2011, DC's line-wide reboot The New 52 reintroduced Quinn in the relaunched Suicide Squad title, which changed the character's personality, design, and origin, replacing her original jester costume with a revealing ensemble and depicting her to be darker than her earlier counterpart. The character took a lighthearted and humorous direction with her second ongoing series in 2013, written by Amanda Conner and Jimmy Palmiotti, which features the character moving to her hometown of Brooklyn and starting her own life in Coney Island. The character has since been depicted as an antihero independent of the Joker and a recurring core member of the Suicide Squad, with Poison Ivy becoming her primary romantic interest. In 2021, DC's line-wide Infinite Frontier relaunch brought Quinn back to Gotham City and reestablished her as a superhero seeking redemption for her past actions, with a new design combining her early and modern appearances.
Harley Quinn's abilities include expert gymnastic skills, proficiency in weapons and hand-to-hand combat, complete unpredictability, immunity to toxins, and enhanced strength, agility, and durability. Quinn often wields clown-themed gag weapons, with an oversized mallet being her signature weapon. The character has a pair of pet hyenas, Bud and Lou, which sometimes serve as her attack dogs. As a trained psychiatrist with a genius-level intellect, she is adept at deception and psychological manipulation.
Harley Quinn has become one of DC Comics' most popular and profitable characters, and has been featured in many of DC's comic books and adapted in various other media and merchandise. DC Comics Publisher Jim Lee considers Harley Quinn the fourth pillar of DC Comics' publishing line, behind Superman, Batman, and Wonder Woman.
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