The Joker is a fictional comic book super villain which has no known origin, but he does have various different ways of being portrayed. The joker is responsible for many of the dark knight's traumas throughout the history of both characters. Some of the biggest heart aches caused by the Joker include:
The paralysis of Barbara Gordon, the death of Robin and the death of Rachel Dawes in the latest version of the Dark Knight movie. The Joker first appeared in the very first Batman comic.
Throughout the ages there have been several different portrayals of the Joker. Some have shown him to be a clever psychopath with a warped sense of humor where as some other versions have shown him as a bumbling clown with more focus on the humor side of the role. In the latest version of the joker in the Dark Knight, the joker is played by heath ledger and comes across as a very inelegant psychopath who seems to be one step ahead of the dark knight at all times.
In most versions of the characters history his skin is bleached white while falling into a vat of boiling acid and in most versions the Joker blames batman for this accident so the hatred begins. Overall I would have to say the joker is probably my favorite comic book villain because he's smart, funny and a real threat to the caped crusader. I'm not the only one who thinks this either as the Joker was voted the number 1 super villain of all time in a recent survey.