10 Worst Things The Joker Has Ever Done To Harley Quinn
6. He Planned To Kill Her In Front Of Batman
At the time of Batman #663, Joker was in a pretty bad place. He had recently been shot in the face by a Batman impostor and was trapped in Arkham Asylum, crippled and unable to talk.
Thinking that his enemy had finally crossed a line, Joker decided to up his game and restyle himself as a "Crime God". The first step was to wipe away all traces of his old life.
He sent Harley to deliver red and black flowers to all his old henchmen. These flowers were laced with a deadly toxin that left a trail of dead clowns all over Gotham. Harley then lured Batman to Arkham Asylum, seemingly for a final showdown with the Joker.
However, once Batman arrived, he revealed that he was really trying to save Harley. He pointed out the red and black flowers as evidence that the Joker's "punchline" was actually to kill her in-front of his archenemy.
Harley didn't believe him, but Batman was proven right when the Joker (now with a deformed reconstructed face) held a razor against her throat. She managed to escape though and even turned against the Joker, shooting him in the shoulder to incapacitate him.