The creators of Batman The Animated Series:We made this character, Dr. Harleen Quinzel, whose is in an abusive relationship with The Joker after he manipulated her and pushed her into snapping, creating her Harley Quinn persona, and developing a severe case of Stockholm Syndrome. This has been pointed out in canon by both Dr. Isley and Batman. Just as Batman is getting through to her, The Joker show ups and pushes her out of a window which results in her being in a full body cast. She has tried several times to mentally heal but has snapped each and every time, truly showing that she is one of the darkest and most tragic characters in this cartoon (and that's saying a lot).
The creators of Suicide Squad:So what you're saying is Harley Quinn is an edgy bubble-gum chewing villain who flashes people and jokes about hearing voices and is the perfect romantic partner for the character played by our crazy Jared Leto?