Comic books have been around for a very long time, with superheroes having led the industry since the 1930s. Over the decades, there have been numerous incarnations and reboots of popular characters such as The Flash and Green Lantern, with legacy characters like Batman and Superman receiving updated origin stories several times over.

From the Golden Age to the Modern Age, comic books have become so perplexing that it is seemingly impossible to jump in without knowing where to start. That is why DC Comics has attempted to attract new readers with their hugely successful DC: Rebirth relaunch.

However, with the advent of the multiverse, via events such as Crisis on Infinite Earths and Flashpoint, understanding the history of DC Comics and its characters has never been more confounding — and that has allowed for some outlandish fan theories to take root. Here are the 15 Craziest DC Comics Fan Theories.

15. Batman kills The Joker in The Killing Joke

the killing joke ending batman joker laugh 15 Craziest DC Comics Fan Theories

Alan Moore and Brian Bolland’s iconic one-shot graphic novel Batman: The Killing Joke is arguably the greatest Joker story ever told, having not only profoundly impacted the Batman Family, but also the caused a seismic shift in the direction of Batman narratives going forward. When the novel released, there were numerous controversies — notably the treatment of Barbara Gordon — but one stuck out to longtime Batman fans in particular: Batman laughing with Joker at the end of the story.

While many see Batman at the end of his rope, simply laughing at the Joker’s joke, some fans believe the Dark Knight, in fact, kills the Joker — which is why it’s called The Killing Joke (something legendary Batman writer Grant Morrison agrees with). Despite overwhelming support for the theory, whether or not Batman does indeed kill the Joker is ambiguous, and something that remains elusive even in Sam Liu’s animated adaptation Batman: The Killing Joke.

14. The Joker is the God of Laughter

The Joker Knows Who Batman Is 15 Craziest DC Comics Fan Theories

One of the biggest mysteries in all of comic book history is just who exactly is the Joker. His name, his origin, and who he was before he became the Clown Prince of Crime — these are all things that have perplexed readers since the character’s humble beginnings in the very first issue of Batman’s self-titled series.

Alan Moore and Brian Bolland’s The Killing Joke attempted a Joker origin story, which has since become canon in the DC Universe; however, the Joker says in the same graphic novel that even he doesn’t know his own origin for sure. Then, during the Darkseid War, when Batman sat upon the all-knowing Mobius chair and asked it what the Joker’s real name was, the chair revealed that there are three Jokers.

To account for the existence of three Jokers (the Golden Age, The Killing Joke, and New 52 Jokers), one fan theorizes that the Joker is, in fact, Gelos, the God of Laughter — someone who “laughs at those in pain” and “jeers at men and women dying.” There are numerous pieces of evidence substantiating the theory, but considering that Gelos could inhabit various hosts only further affirms the possibility.