Because the popular DC Comics character has been known to switch sides between villain and hero, here are the 5 most heroic things that Harley Quinn has done, and the 5 most devious things she has committed.
Before becoming known in the criminal underbelly, Harley Quinn had a promising career in the medical field as Doctor Harleen Frances Quinzel. In Gotham City, Dr. Quinzel served as a prominent psychiatrist in Arkham Asylum, where she met the insane clown prince of crime, The Joker. After becoming the Joker's accomplice for so many years, Harley pays for her previous crimes by saving the world with the other members of the Suicide Squad.
Created by Paul Dini and Bruce Timm, Harley Quinn made her first villainous appearance to television audiences in Batman: The Animated Series. After her introduction in the episode entitled, "Joker's Favor," Harley then made the leap to the comic book page in The Batman Adventures #12. Ever since the reboot of The New 52 era, Harley has moved away from her dark past as Batman's enemy. Quin managed to turn her wayward life around as an anti-heroine, but there are still times when her relationship with the Joker comes back to haunt her.
10 Devious: Tommy Elliot's Death
In writer Jeph Loeb and artist Jim Lee's Batman: Hush, Harley suddenly manages to interrupt Bruce Wayne's date with Selina Kyle at the opera, Pagliacci. During the robbery, Harley jumps out and steals a precious item from Bruce's childhood friend, Tommy Elliot.
Bruce is too late to stop Tommy from chasing after Quinn into the back alley. Batman ends up finding Tommy dead and the Joker holding the gun that killed him. Harley participated in a grand scheme orchestrated by the criminal mastermind, Hush, to mentally break the dark knight.
9 Heroic: Saves Poison Ivy
In Tom King and Mikel Janin's Batman run, during the "Everyone Loves Ivy" story arc, the rest of the world has fallen completely under the control of Pamela Isley. Though Batman and Catwoman have been able to escape Poison Ivy's mind-controlling influence, the caped crusader realizes he's not strong enough to defeat her.
Reluctant at first, Harley only gets involved in the battle because she wants to save Pamela from losing control. With so much love and care, Harley holds onto Ivy and tells her that they are both hurting; they should be together.
8 Devious: Creates Joker Boy
In the animated Batman Beyond: Return of the Joker, the elderly Bruce Wayne reveals to his new protege, Terry McGinnis, what really happened during his last confrontation with the clown prince of crime. Harley ended up kidnapping his unsuspecting sidekick, Tim Drake, who was out in patrol wearing the Robin costume.
In the ruins of Arkham Asylum, Harley used her psychiatric degree to psychologically torture Tim, forcing him to reveal Batman's secret identity. By the time she was done experimenting with Robin, Tim came out dressed like a boy-sized version of the Joker.
7 Heroic: Heroes in Crisis
In Tom King and Clay Mann's superhero mystery, Heroes in Crisis, Poison Ivy and the other patients at the rehabilitation center, Sanctuary, have been found murdered. As one of the survivors of the massacre, Harley is desperate to find out who killed Ivy and blames the time-traveler, Booster Gold, as the real culprit.
During her mental breakdown, Harley reveals to Batgirl how Joker physically and mentally abused her for so many years. Knowing how much Ivy meant to her, Batgirl asks Harley to join the investigation and solve the murder mystery.
6 Devious: Joker's Face
In Suicide Squad #7, the Black Drive has driven all the prisoners at Belle Reve Penitentiary insane. After causing a bloody riot, Harley makes her escape to locate the last remains of Joker's face. Unfortunately, Deadshot finds himself tied up in a chair and wearing the Joker's face she stole.
Unwilling to release him, Harley ignores Floyd Lawton's constant pleas for help and keeps referring to him as Mr. J. After planting her lips on Lawton, with the Joker's face on him, Harley demands to know why her former lover left her all alone.
5 Heroic: Black Canary's Gift
During Injustice: Gods Among Us: Year Two, Harley has been hiding out in the Arrow Cave and gets discovered by Black Canary. Just when the two are about to start their hand-to-hand combat, Black Canary suddenly fells sick, like she's about to vomit. Because she used to be a doctor, Harley recognizes the symptoms of morning sickness and realizes the super-heroine is pregnant.
During a hospital visit, Harley has a bunch of presents, including a muzzle, for baby Connor. Harley advises using the muzzle in case Connor has his own canary cry.
4 Devious: Exploding Video Games
In the one-shot special by Matt Kindt and Neil Googe, Detective Comics #23.2 examines how the former Arkham Asylum psychiatrist ended up becoming the Joker's main squeeze. With Harleen gone and her other personality taking control, Harley comes up with a deadly software that will install itself into every handheld gaming system.
The deadly software triggers every video game to instantly explode and lights up half of Gotham City on fire. In order to be with the Joker, Harley understands that she cannot show any remorse over the deaths of numerous children.
3 Heroic: The Secret Daughter
In the Injustice: Gods Among Us comics, Lucy Quinzel is the daughter of the Joker and Harley Quinn, but she doesn't even know that. Harleen's sister, Delia, takes care of Lucy while Harley keeps her a secret from the Joker. Wanting to keep her daughter safe, Harley pops in from time to time, sending in cash and clothes.
While growing up, Lucy refers to Harley as her aunt and Delia as her mother. After Lucy is kidnapped by the New Suicide Squad in Injustice 2, Harley head-butts Ra's al Ghul as she comes to her daughter's rescue.
2 Devious: Tortures Flash
In the Injustice: Gods Among Us: Year 2 #22, The Flash ends up strapped to an operating table. Taking down Batman's resistance team, The Flash has been on the side of Superman's Regime. He didn't realize his loyalty to Superman would be questioned after being captured. While playing around with his lightning bolt pieces, Harley reveals she has been ordered to reprogram the Flash.
During the brainwashing session, Harley intends on using electro-shock therapy and puppets on the captured speedster. Even though she is going to enjoy torturing the Flash, Harley promises she's going to be professional about it.
1 Heroic: Stops Enchantress
Even in live-action form, Harley Quinn (Margot Robbie) realizes it's up to the bad guys to save the world in the Suicide Quad movie. With the remaining squad members exhausted from battle, Harley gives Task Force X the time they need while she distracts their opponent, Enchantress (Cara Delevingne).
In exchange for her allegiance, Enchantress offers to fulfill Harley's hidden desires, such as a family and a loving husband. While pretending to be interested in the deal, Harley gets close enough to slice Enchantress with her sword and rip out her heart.