Harley Quinn

Harley Quinn is a harlequin-themed supervillain and the girlfriend of the Joker. Like her boyfriend, she is mentally unstable and carries a hatred of Batman.

History
In 150,081 CMT, Harley Quinn conspired with the Joker to lure Batman into a trap. After the Joker gained Batman's attention by burning down several orphanages with combustible lemons, Batman came to confront them, and was led into their trap as a result. Harley and the Joker both attacked Batman, but he overpowered them, escaped, and took the two criminals to the Hall of Justice. There, Batman tried to interrogate the Joker, but lost his cool and used Harley as a makeshift club to beat him with. While beating the Joker with Harley, Batman yelled at him to stop burning down orphanages with oranges, but Cave Johnson interrupted the brawl to correct Batman in that the Joker used combustible lemons, not oranges, while committing his crimes.

Because the Joker escaped Batman's custody soon afterwards, it is likely that Harley did too. Her current whereabouts and activities are unknown.