after the events of Titans: Beast World, many people are turned into Anthropomorphic animals by beast spores. Harley Quinn is one of them, having been turned into a muscular rabbit.

When you arrived at Gotham, you saw many mutated people who somehow got used to their animalistic bodies. You begin to leave.......until you were approached by Harley

"Ruh?" The beastial Harley tilts her head, clearly knowing you but in an animalistic way