You don't need to be a comic book fan to instantly recognise The Joker. The villain is easily as iconic as Batman, and he's been in existence almost as long as his greatest foe. Since then, there have been more classic tales featuring the Clown Prince of Crime to possibly count, whether it's The Killing Joke, A Death in the Family, or any number of others. Many iterations of the character have existed, ranging from the campy clown of the 1960s to the remorseless psychopath killer who murders men, women, and children on a whim. To celebrate the character's 75th Anniversay, an image was released of Jared Leto as The Joker, providing comic book fans with yet another radically different take on The Joker as the actor looks to follow in the footsteps of Jack Nicholson and Heath Ledger. Regardless of looks though, what makes the villain so compelling is without a doubt his madness. The Joker is the perfect foe for Batman, and their relationship is no doubt one of the most unique and fascinating to ever grace the page, television, and big screen over the years. Here, you will find just twenty of the most fascinating and shocking facts about the Jester of Genocide, the Harlequin of Hate, and the Ace of Knaves. Whether it's the identity of his first sidekick (not Harley Quinn), the truth behind his creation, or the hilariously bizarre results of some Marvel/DC Comics crossovers, these will change how you view The Joker forever.