Joker Solo Movie: 10 Origin Stories It Could Adapt

Fan theories. You've got to love 'em, and this one would be a bombshell of nuclear proportions if it turned out to be true.

Bat historians have attempted to tie Batman and the Joker together by blood for a while now, with some claiming that he's Bruce Wayne's long lost brother.

Fleeting references to a Thomas Wayne Jr. have been kicking about in DC Comics continuity for generations, a character who is presumed to have died from some kind of serious head injury during childhood.

Conspiracy theorists have jumped on this and speculated that the youngster actually survived and spent his early years locked away in a sanitarium, suffering from brain damage, only to break out years later to taunt his brother, Bruce.

There's an undeniable connection between Batman and The Joker and they're always drawn to one another, and that has only added fuel to the fires of this theory.

Perhaps its most compelling piece of evidence is the fact the Caped Crusader is unwilling to let his arch-enemy die. Subscribers argue that he subconsciously recognises his kin, and complex psychology will always prevent him from solving Gotham City's clown problem once and for all.

Although the Thomas Wayne Jr. theory has never been endorsed by DC Comics, if the Joker movie is looking for a twist nobody would see coming, this is one ace it could plant up its purple sleeve.