- "You wanna play? Okay, let's play!"
- ―Harley Quinn[src]
Harley Quinn is a villain in LEGO Batman: The Videogame. Dr. Harleen Quinzel was a budding psychiatrist with an obsession for the criminally insane, specifically the Joker. While serious business at first, an interview turned into a date after the Joker twisted her mind with possibly false origin stories. After coming to the conclusion that her "puddin" didn't belong in Arkham Asylum, she donned a jester's costume and became his on-and-off girlfriend, Harley Quinn!
Having escaped Arkham Asylum, Harley Quinn allied herself with The Joker and helped with his plan to flood Gotham City with laughing-gas. She aids the Joker by capturing Commissioner Gordon and fighting Batman and Robin. She fails to defeat them, however, but the Joker still allows Quinn to help in his plans, and it is Harley herself who helps finish the final piece of the plan by rigging Gotham Cathderal with bombs and Joker Gas. When the Dynamic Duo arrives at the Cathedral, Harley delays the Duo by battling them from a ledge, allowing Joker enough time to race up to the Bell Tower. When she is again defeated, she retreats into the Cathedral to join Joker in the Bell Tower. She is knocked out by Batman and Robin in a final, grueling battle with Joker and, despite the Joker's surprise attack on Batman and Robin, she is captured and sent back to Arkham Asylum. She is last seen in her cell, fixated on a poster of the Joker.
Harley Quinn reappears in LEGO Batman's sequel, where she is a member of the gang led by The Joker that attacks the Man Of the Year Awards at the game's beginning. When Batman and Robin appear on the scene, Harley stays behind to fight them whilst the other villains escape. She is defeated and returned to Arkham Asylum. She is later freed by Lex Luthor's Deconstructor and escapes with the other villains, only to be apprehended by Batman again. However, Harley along with the other villains successfully escape a second time, where she travels to Amusement Mile alone. Harley can be optionally fought and unlocked as a playable character.
- Harley Quinn is capable of performing a Double Jump
- She can use her over-sized hammer to attack opponents
- She can perform backflips due to her athleticism.