Harleen Quinzel, a.k.a. Harley Quinn, is the Joker's sidekick. She is also partners-in-crime with Poison Ivy.
History[]
The Face of Two Worlds[]
An escape from Arkham Asylum and a Kraang portal brings Harley Quinn and the Joker to New York City.
The Clown and The Clan[]
After escaping the Arkham Asylum and using a pair of Kraang portals to enter New York City, the Joker and Harley meet with the Shredder in Warehouse 17 on the docks. Incensed by the Joker’s behavior, Shredder orders his mutants Bebop and Rocksteady to attack, but Joker counters with an exploding rubber chicken. To make matters worse, he and Harley have attached dozens of rubber chickens to the ceiling, all filled with sticks of dynamite.
Greener on the Other Side[]
Upon Shredder’s refusal of a partnership, Joker tells him he’ll take the whole city for himself. Shredder’s other mutants step forward and Harley is thrilled to see Tiger Claw. She asks Joker if she can pet the kitty, but Tiger Claw tells her only if she doesn’t value her hand. Joker then sprays Joker Gas in Shredder’s face, sending him into fits of laughter which incapacitates him.
To Laugh so not to Cry[]
Joker has taken over Foot Headquarters. Elsewhere, Harley is gathering the toxic chemicals needed so that they can make a batch of Joker Gas large enough to cover the whole city. By the time Harley and the Footbots who are helping her return to the Foot Headquarters, Batgirl, April O'Neil and Donatello have arrived. Harley tries to pretend innocence, pleading with Batgirl that “he’s gone too far”. She offers to prove what she means and rushes to open a pair of doors inside the warehouse, presenting a pair of mutant hyenas – Bud and Lou. The fight takes all of them to the throne room, where Batman, Leo and Raph join the battle. After defeating Bud and Lou, Batman knocks out the Joker and Don waylays Harley.
Through the Looking Glass[]
Batman and the Turtles cart their prisoners the Joker and Harley around with them as they track down the Mad Hatter.