As long as there has been the Batman, the Joker hasn't been far behind. He is the archenemy (arch nemesis) of Batman, having been directly responsible for numerous tragedies in Batman's life, including the paralysis of Barbara Gordon (as told in "Batman: The Killing Joke", a one-shot graphic novel written by Alan Moore, drawn by Brian Bolland, and published by DC Comics in 1988) and the death of Jason Todd, the second Robin in 1988's "Batman: A Death in the Family" storyline.
This is Mattel's The Joker from Season 1 of "The Batman" animated series. I'd covered The Batman HERE and Bruce Wayne HERE earlier. The insane appearance of this re-imagined Joker makes him look extremely dangerous. The Joker comes in a straitjacket (albeit a rather bright neon looking one) from his recent escape from Arkham Asylum.
Throughout the character's long history, there have been several different origin tales; they most commonly depict him as falling into a vat of chemical waste, which bleaches his skin and turns his hair green and his lips bright red, giving him the appearance of a clown. This was also depicted in Tim Burton's "Batman (1989)" with Jack Nicholson appearing as The Joker.
Director Christopher Nolan has mentioned that "The Killing Joke" served as an influence for the version of the Joker appearing in "The Dark Knight (2008)". Heath Ledger, who played the Joker, stated in an interview that he was given a copy of "The Killing Joke" as reference for the role. The film lifted the concept of the Joker trying to drive a well-regarded person insane, as well as the Joker's inconsistent "origin stories".
This incarnation of the Joker sports a purple and yellow straitjacket, fingerless gloves, bare feet, wild green hair and red eyes. The Joker also moves and fights with a Monkey Kung Fu-like style, using his feet as dexterously as his hands, and often hangs from the walls and ceilings.
They call this release the "Hammer Strike Joker" because he comes with a Giant Hammer, much like the coin-operated Arcade game where you use a mallet to hammer and strike the moles as they pop up from the "ground".