Editor's note: this post is FILLED with legitimate Batman-related spoilers, so read with caution.
In the nearly seventy years since he’s appeared in DC Comics, the Joker’s identity has been a long-running mystery. Even the Joker himself isn’t exactly sure of his origin.
Sometimes he’s a small-time criminal-turned-victim who falls into a vat of toxic chemicals that permanently bleaches his skin white, turns his hair green, and leaves his mouth forever red and disfigured. Sometimes he’s just a terrorist psychopath with no real backstory. It really depends on who's writing him.
Right now, though, Reddit's blowing up with a fan theory that the Suicide Squad's Joker, played by Jared Leto, is actually a twisted, psychotic version of Jason Todd, the second Robin. Let that wash over you for a second.
The key to understanding this theory, popularized by Reddit user Jason-G169, is watching the trailers for Suicide Squad and Batman v Superman: Dawn of Justice, and knowing a little bit about the Joker's storied history of torturing people.
In both trailers there are a number of scenes that reference things that appear to have happened before either of the films take place. Of particular importance are these two shots featuring Ben Affleck as Batman:
Batman v Superman takes place in the same universe as Zack Snyder's Man of Steel, but at an undetermined point in the future. In this world, Jason-G169 theorizes, Batman finally teams up with Robin, though their partnership is cut short when Robin is murdered.
In the trailer, we briefly see a Robin suit in the Batcave that's painted with the words: "HAHAHA, Joke's on you, Batman." Later in the trailer, Wayne unfolds a news clipping accusing him of letting his "family die." The two sets of handwriting are awfully similar:
Fans are assuming that the writing on Robin's suit is the Joker's because of its green-ish hue and the similarity between the "HAHA" and the "HAHA" tattoos that the new Joker has inked all over his body.
The implications of the newspaper clip get a little bit deeper and require that you've got some familiarity with the Batman comics. Batman frequently refers to his sidekicks and bat-themed teammates over the years as his "family." For the most part, the family's secret identities have remained just that: a secret.
If it's the Joker that's writing this note, though, how would he know to refer to the dead Robin as a member of his family? Moreover, what "joke" is Robin's suit referring to? The simple answer is that the Joker killed Robin and is merely taunting Batman. The more interesting answer that Jason-G16 and other comic book fans want to believe: this Joker and that Robin are one in the same.
In order for this theory to work, we've got to assume that a few different things are true. First, the Robin referenced in the film would actually have to be Jason Todd. In the comics and some of the more recent Arkham video games, a particular instance where the Joker tortures and murders Jason Todd is explored for dramatic effect.
In 2000's direct-to-DVD movie Batman Beyond: Return of the Joker, however, the Joker stops short of killing Tim Drake (the third Robin) in favor of gruesomely torturing him and turning him into the Joker Jr. Drake, being mentally broken, laughs maniacally in front of a horrified Batman before ultimately shooting the Joker. Some ans of Jason-G16's theory are rallying around the idea that Batman v Superman might draw from this particular interpretation of what drives Robin insane.
For this to be true, though, it would require that there actually be two Jokers—the one that tortures Jason Todd, and the one that becomes the "new" Joker (played by Jared Leto).
There are other potential clues that back the theory up. Below the new Joker's left eye is a "J" tattoo that many believe is a reference to the "J" brand the Joker bestows upon Jason Todd in the recently released Arkham Knight.
Also, Leto's Joker appears to have a winged animal tattooed on his bicep that many are claiming is another callback to his previous life as Jason Todd.
On a deeply nerdy level, this fan theory is incredibly satisfying because it dovetails nicely with with how DC comics have dealt with the death of a Robin in the past. Jason Todd is the most high-profile Boy Wonder to have died and making him the new Joker would still allow for Batman v Superman to introduce Dick Grayson, the first Robin, who eventually went on to become the hero Nightwing.
Snyder's son Eli is rumored to make a cameo as a Boy Wonder in his father's upcoming film, though there's no telling just which Robin he might be. Until March 25th, 2016, your guess is as good as ours.