Source of image from: DCAU WikiIn Batman Beyond: Return of The Joker, six new teenage rogues work for the clown prince of crime. The most popular of the group are twin sisters both sharing the name Dee Dee. Both have Raggedy Ann-like faces while dressed in a certain manga fangirl look.
Source of image from: The World's Finest
At the end of the film Harley Quinn is revealed to be their grandmother. Not too surprising. But it makes you wonder, if Harley is their granny, then does that make Joker the lucky grandpa?
Dee Dee may take on Harley's looks, but they can't compete with her cute charming personality. They are more brutal, thrill-seeking and are so disrespectful of their "poor grandmother's heart." Kind of similar to how Joker puts up with everyone.
Batman Beyond: Return of the Joker belongs to DC Comics/Warner Bros.