The Red Hood was once a small time criminal who was trying to escape Batman in a chemical factory. The Red Hood fell into a vat of toxins which turned his hair green, bleached his skin white, stained his lips red, and stretched them out into an everlasting smile; it gave him the appearance of a crazed clown. The Red Hood was driven insane by this reflection, and renamed himself The Joker. Joker became Gotham's most sadistic and twisted crime boss and that he is insane, but also a genius, having knowledge of chemistry, physics, and engineering; Joker invents gag-based gadgetry whilst concocting criminal schemes. The Joker also cheats death frequently, having been thought killed several times only to come back and wreak havoc once more. He has many minions serving under him, most notably his self-proclaimed lover, Harley Quinn, who herself was once his psychiatrist at the Arkham Asylum, and fell in love with him there. The Joker is a mass murderer and has been known to kill many people, even his own henchmen.
- Ability: Joker Gas (Can be used to ignore one attack per day)
- Weakness: Bursting into laughter (Can't attack a third time a day if the first two fights were successful)