Real Name: Jack Napier
Current Alias: The Joker
Aliases: The Clown Prince of Crime, Patient Zero, Case File 223
Faction: The Council
Base Of Operations: Gotham City
Alignment: Psychotically Evil
Race: Human
Citizenship: U.S. with Criminal Record
Marital Status: Single
Occupation: Criminal
Height: 6',1"
Weight: 185
Eyes: Black
Hair: Green
Place of Birth: Gotham City

Abilities:

Demented Brilliance: He is as brilliant as he is insane and he has sufficient expertise in chemistry and physics to be able to invent gadgetry and concoct elaborate schemes.

Gadgets: His equipment included card-shaped blades, guns (of the trick and real variety), joy buzzers (which electrocuted the victim), a wide variety of laughing gases (which incapacitated the victim with laughter), and his deadly Joker Venom. Most famously, Joker had a flower attached to his suit. This flower emitted a wide variety of chemicals, depending on the situation and Joker's mood. Laughing gas and acid were popular variants, but the possibilities were limited only to the Joker's mind.

Death Defiance: The Joker also seems to have a strange relationship with death, constantly surviving and coming back from potentially fatal things - including long falls, explosions, vehicle crashes, to name a few-that should by all rights have ended his career.

Background/History: Prior to his transformation, Joker was an assassin working for Salvatore Valestra, Buzz Bronski, and Chuckie Sol. The mob sent him to kill Carl Beaumont, a businessman who had embezzled from them. Sometime later, he formed his own gang and robbed the Ace Chemical plant. Batman arrived, and in the ensuing scuffle, the thug fell into a vat of chemicals. The chemicals inside the vat beached his skin white, turned his hair green, made his lips bright red and completely warped and destroyed his sanity, transforming him into the Joker. After taking up his new identity, Joker would establish himself as one of the main criminal powers in Gotham and became a recurring enemy of Batman. During one instance, while placed in Arkham Asylum, he manipulated his psychologist Doctor Harleen Quinzel into falling in love with him, driving her to join his gang as his chief flunky, Harley Quinn.

Weakness
Joker's weakness is his pride and need to be in the spotlight. True that Batman is the one audience member he can always count on, but the show is not just for him. Joker plans his heists and jokes with the intention of everyone in Gotham (and hopefully the world) will see it and know that Joker did this.