The Joker is one of the main villians, as well as the archnemesis to Batman, in the DC Comics universe. His first appearance was in the Batman #1, which came out in 1940. While he is one of the most popular characters in the series, there are many different stories as to his actual origins, all leading to falling into chemicals making him what he is today. He doesn't have any actual powers, making him similar to Batman, with him using gadgets and tricks to terrorize Gotham City.
The Joker has appeared in almost every form of media, as well as many video games based on the DC Universe. These include the Batman: Arkham series, DC Universe Online, Mortal Kombat vs. DC Universe, Injustice: Gods Among Us, and many more.
