The Joker was sick and tired of getting fire thrown at him. This was the second time in as many weeks that he'd been harassed by that little fire-bending bitch.
After crawling back home from his secret lair - that is to say, in his abandoned meat factory - the Joker was kind of incapacitated at the moment. His forearms were definitely going to be burnt and his face probably had an unhealthy tan to it, but the worst thing was the patch of hair missing at the side of his head and his missing eyebrows.
He was a vain man, after all.
"Harvey," he called, in his best and most put-upon tone, "I need help!"