The Joker is a psychotic criminal from Gotham City. His appearance and personality is that of a clown, and he pulls tricks and assassinations that are deadly and clever. He is the archenemy of Batman, although he plays a minor role and makes occasional cameos in Teen Titans Go!.
The Joker was once a standard criminal who was foiled by Batman whilst in a chemical factory. During the struggle he fell into a vat of chemicals. This accident bleached his face white, dyed his hair green, turned his lips blood red, and gave him a permanent smile, transforming him into the Joker. His disfigurement also made him lose his sanity, and he would go on to become one of Gotham City's most feared super villains.
In Season 3, Joker appeared in the episode "Pyramid Scheme", as he paid money to Raven, Cyborg and Starfire. His next appearance was in "The Titans Show", where he was revealed to be one of the viewers in Control Freak's summer event.
in Season 4, Joker made a cameo appearance in the episode "The Streak", where he was shown to be beaten by Kid Flash and then shown in the song "It's Not About the Parts", locked up alongside Slade, The Penguin, The Riddler and Mr. Freeze. In "TV Knight 2", he and The Penguin were invited to watch TV with Batman and Commissioner Gordon. When Alfred caught them, The Joker and Penguin escaped. He then appeared at the end of the episode bringing coffee for Batman and Commissioner Gordon, while The Penguin brought them a huge umbrella, to protect them from the rain. Then the four of them share a hearty laugh. He later made an appearance in "Mo' Money Mo' Problems", accompanying Catwoman, The Penguin, The Riddler and Poison Ivy to invade and rob Wayne Manor and easily beating the Titans (namely squirting Robin's eyes with a stinging gas). But in the end, he was defeated by Alfred, who tickled him with a broom, and then beat him with it.
In Season 5, Joker appeared in a flashback, where he was shown to be captured by Batman and Robin, laughing all way to prison.
In "Bat Scouts" he was reading 101 Killing Jokes, when the Titans, minus Robin trespassed into Arkham Asylum and chased them off. Later, he was shown to be terrorizing the people of Gotham City. Nonetheless, he was defeated by Cyborg, who did the Batusi, which cringed The Joker. Cyborg then punched him into a street light pole, causing The Joker to faint. He and his cohorts were teleported back to Arkham. In "Egg Hunt", Joker and the rest of the inmates were freed by the Titans, who could search the asylum in peace.
The Joker usually dresses in purple, custom made clothes. He has a light green undershirt and a flower, which shoots acid. He has white skin, a pointy nose, and green hair. His overall appearance is based on a clown, as his name implies.
- Serious Business (Beast Boy dressed up)
- Real Boy Adventures (debut, cameo)
- Cool School (cameo on truck)
- Yearbook Madness (referenced in yearbook)
- Beast Man (cameo)
- 40%, 40%, 20% (cameo on cereal bowl)
- Pyramid Scheme (cameo)
- Batman v Teen Titans: Dark Injustice (cameo)
- Rad Dudes with Bad Tudes (cameo on sticker)
- The Titans Show (cameo)
- Booby Trap House (cameo on baby pool)
- The Streak
- BBRAE (cameo as a painted face on a ferris wheel seat)
- TV Knight 2
- Mo' Money Mo' Problems
Teen Titans Go! to the Movies (cameo)
- Claus of the Batman (cameo on poster)
- The Joker's first design in this series is very similar to his revamped design from The New Batman Adventures.
- During the audio commentary on the Superman: The Animated Series episode "World's Finest" the producers state that they regret the stylistic change for the Joker, they also admit that removing his red lips was a mistake and that doing so was Teen Titans TV Series creator Glen Murakami's idea.
- In the DCAU and many other appearances he was voiced by Mark Hamill, who is best known for playing Luke Skywalker in the Star Wars films.
- At San Diego Comic Con 2017, Tara Strong stated that she would love it if Mark Hamill guest starred as The Joker in a future Episode.
- The Joker is one of the few characters to have multiple different design throughout the series.