In many ways, Batman and the Joker are the ultimate enemies. Diametrically opposed, but two sides of the same coin. If Batman is order, the Joker is chaos. The Clown Prince of Crime is the first villain you think of when you think of Batman, and it's no wonder; many of the Dark Knight's definitive stories, be they in the comics, the animated universe or the movies, have seen him matching wits with his purple-clad foe.
However, when it has come down to it, Bruce Wayne has often spared the Joker's life, regardless of how far the grinning criminal has pushed him. And in return, the rogue has even saved Bats a few times himself. Of course, Gotham's Guardian has sworn never to take a life, so it is somewhat understandable he doesn't break this rule, even if it is for a man who has done the things the Joker has done.
But when the Jester of Genocide saves Master Wayne, it is somewhat more perplexing, lending credence to the idea that the Joker truly sees Batman as essential to his own existence; that one cannot exist without the other.
With that in mind, then, here are ten times these famous rivals have come to each other's rescue.
10. The Batman Who Laughs - Dark Nights: Metal
Created by Scott Synder and Greg Capullo, the Batman Who Laughs is a terrifying alternate version of Batman, and one dangerous enough to even cause the Joker to join forces with his arch-enemy in order to defeat. The Batman Who Laughs is essentially a version of Bruce Wayne from Earth-22 who killed his Joker in a fit of rage, getting infected with Joker Venom in the process. This causes Master Wayne to become unhinged, turning into a kind of monstrous amalgamation of the two storied enemies.
This makes some sense as something for writers to explore, given how it has often been asserted that they are so similar. After the unlikely duo finally manage to defeat the Batman Who Laughs, the regular Dark Knight comes close to replicating the very event that cause his alternate reality self to end up as the monster they have just defeated, beating his vanquished foe almost to death.
Alfred begs Bruce to stop, but only the Joker is able to put an end to his untethered rage, firing a non-lethal shot at Batman, rendering him unconscious, and saving him from himself in the process.