Everyone interprets that name differently, feels a slightly different shudder, evokes contrasting connotations of dread... but the net result is the same: fear.
We all recoiled in horror when he paralysed Barbara Gordon in The Killing Joke, and held our collective breath when, after murdering an entire talk show crowd, he proceeded to snap his own neck in The Dark Knight Returns.
But what of his lesser-known exploits, those horrifying stories you may not have read?
The Joker is undoubtedly Batman’s greatest, most detested foe - one with no super, meta, nor supernatural powers to speak of, but whose notoriety and legend are born of his complete lack of human emotion. However, there is still a sense of the familiar with the character, owing to the fact that he's by far the most prolific villain in DC's comics.
This is what makes those lesser-known tales featuring the Clown Prince of Crime so special, as it rekindles those terrifying first memories every fan had the first time they encountered the character. Hidden gems by any other name.
Here, then, are ten of the most deplorable, most terrifying Joker stories you've never read...