The character The Joker did not originate from fanon, and more information can be found on their respective wiki(s). You may read more about it on the following wiki(s):

I believe whatever doesn't kill you, simply makes you... stranger
The Joker

The Joker
An animated photo of The Joker from Justice: Apocalypse
Full Name The Joker or simply Joker
Current Age Unknown
Date of Birth Unknown
Gender Male
Species Human
Location Gotham City
Current Status Alive
First Appearance Batman #1 (April 25, 1940)

The Joker is a fictional DC comics villain and the main antagonist in the Batman series and appears throughout various DC spin-off television shows and making cameos in various video games.


Lego Batman 4: Marvel vs. DC

The Joker is one of the main playable characters of a crossover between Lego Batman (hence the title) and Lego Marvel. He is one of the supervillains led by Lex Luthor to take down Hydra - Luthor not wanting to be outclassed by Baron Zemo. This group ends up teaming up with the main heroes consisting of the founding members of the Justice League, several of the Avengers, Spider-Man, Wolverine, the Thing, and Deadpool for the final battle against Zemo.