Joker is a psychotic supervillain and a member of the Injustice League.
The Joker is a dangerous and psychopathic criminal. Although he looks like a clown, he is never to be underestimated. He is cruel, sinister, manipulative and above all, completely insane. He also claims to have multiple personalities and has a tendency to break the fourth wall.
The Joker is a tall, slender man, with chalk white skin, ruby red lips and a head of bright green hair falling down in a mop style. His most distinguishing feature, however, is his massive and wide smile that is constantly on his face, giving him a sinister sort of appearance at all times. He is most commonly seen wearing a purple suit with a flower on his lapel, skinny leg pants, a skinny purple tie and a silver chain at his waist.
They orchestrated a plan involving controlling plants that attacked different parts of the world, adding his own Joker venom spores to some of them. He controlled all the plants in the worldwide assault. Eventually, the Team found the headquarters of the Injustice League in Bayou Bartholomew. After most of his teammates had joined the fight and the plant was destroyed, Joker tried taking down Robin. The Boy Wonder managed to evade his knife long enough for the Justice League to arrive, and Batman quickly disarmed the Joker. Faced with the surrender of his teammates, he released the Joker venom from the plants. Aqualad, as Doctor Fate, sucked the venom away, and Joker surrendered this time. 
- Knives: Joker uses jackknives, occasionally two at a time.
- Joker venom: a chemical which, when inhaled, causes its victims to laugh uncontrollably until they die with a wide grin on their faces.
- Young Justice #1: "Haunted" (illusion)
- Young Justice #2: "Monkey Business" (illusion)
- 114. "Revelation"
- 125. "Usual Suspects" (photograph)
- 126. "Auld Acquaintance" (flashback, no lines)
- The Joker is the archenemy of Batman. Making his debut in Batman #1 (1940), he has represented chaos opposite Batman's order ever since. He is responsible for crippling Barbara Gordon and killing Jason Todd.
- This is his tenth animated appearance. He has appeared in The Adventures of Batman, in two episodes of The New Scooby-Doo Movies, The New Adventures of Batman, Super Friends (but only in The Super Powers Team: Galactic Guardians), the DCAU (Batman: The Animated Series, Batman: Mask of the Phantasm, Superman: The Animated Series, The New Batman Adventures, Batman Beyond: Return of the Joker and Justice League), The Batman, and Batman: The Brave and the Bold. He also appeared in the DC animated films Justice League: The New Frontier, and Batman: Under the Red Hood.
- Phil Bourassa based the Joker's design, mostly his silhouette, on the Japanese manga character Lupin the Third. He also drew inspirations from Spike Spiegel, the Rat Pack and the 1960's Yakuza.
- ↑ Weisman, Greg (2012-01-10). Question #13943. Ask Greg. Retrieved 2012-01-10.
- ↑ 2.0 2.1 Weisman, Greg (2012-11-27). Question #17115. Ask Greg. Retrieved 2012-11-27.
- ↑ 3.0 3.1 3.2 3.3 Hopps, Kevin (writer) & Chang, Michael (director) (October 14, 2011). "Revelation". Young Justice. Season 1. Episode 14. Cartoon Network.
- ↑ Aureliani, Franco, Art Baltazar (w). Norton, Mike (a). Sinclair, Alex (col). Lanham, Travis (let). Chadwick, Jim, Scott Peterson (ed). "Haunted" Young Justice 1 (February 16, 2011), New York, NY: DC Comics
- ↑ Weisman, Greg (2011-09-16). Question #13499. Ask Greg. Retrieved 2011-10-24.
- ↑ Aureliani, Franco, Art Baltazar (w). Norton, Mike (a). Atkinson, Zac (col). Lanham, Travis (let). Chadwick, Jim (ed). "Monkey Business" Young Justice 2 (March 16, 2011), New York, NY: DC Comics
- ↑ Weisman, Greg (2013-03-14). Question #18897. Ask Greg. Retrieved 2013-11-19.
- ↑ Weisman, Greg (2012-01-30). Question #14088. Ask Greg. Retrieved 2012-01-31.
- ↑ Harvey, James (2012-03-02). Backstage - Interview with Phil Bourassa. The World's Finest. Retrieved 2017-08-25.