One of the things that makes the Joker so terrifying is that - despite threatening Gotham City and even on occasion the world - he does it all without powers. The Clown Prince of Crime is a tactical genius and a limitless agent of chaos, but unlike Gotham's other villains, he can't control plant life, make people see their worst fears, or return from the dead. However, as terrifying as Joker is without powers, there is one occasion where he's all but guaranteed to gain new abilities - when DC crosses over with another fictional universe.
DC has crossed over with franchises from Teenage Mutant Ninja Turtles to Scooby-Doo, and when it does, Joker usually takes the opportunity to get a superpowered upgrade themed after whatever franchise he's currently visiting. This is particularly interesting for fans, as they get to see what Joker would be able to do if he developed superpowers that matched his usual tactics and obsessions.
In the worlds of Alien, The Mask, Judge Dredd and more, the Joker is an even deadlier foe - one who finds new ways to challenge Batman like never before. Here are the five biggest power upgrades Joker got by stepping out the DC Universe.
5 Acid Spit (Alien)
In Ian Edginton and Staz Johnson's 2002 Batman/Aliens II, Batman is forced to deal with a White Xenomorph that runs amok in Gotham City. While Batman is able to eventually subdue the monster using one of Mr. Freeze's ice guns, he discovers a government scientist named Dr. Fortune has been creating Xenomorph hybrids using human DNA, and most of this DNA has been coming from Arkham Asylum inmates. The result is a Joker/Xenomorph hybrid who takes Joker's iconic acid-spewing flower to a new level. Added to the usual acid blood all Xenomorphs possess, the Joker-Alien can spit deadly acid while also keeping the Gotham villain's twisted sense of humor.
4 Healing Factor & Razor Claws (Amalgam Comics)
DC is no stranger to huge crossover events and one of the absolute biggest crossovers that DC ever had was Amalgam Comics. After the events of DC vs Marvel, both universes were fused into the Amalgam universe, a place where DC and Marvel's characters merged together. This had fairly interesting effects, such as Wolverine and Batman being fused into Darkclaw, and Sabertooth and Joker being naturally fused into the villain Hyena. Hyena first appeared in Legends of Darkclaw #1 by Larry Hama, Jim Balent, and Ray McCarthy. As Hyena was a fusion of Joker and Sabertooth, he inherited Joker's insanity and genius-level intellect, along with Sabertooth's healing factor, enhanced senses, and razor-sharp claws. This made Hyena one of Joker's most dangerous forms - and one with a perfect name.
3 Immortality & Killer Laugh (Judge Dredd)
One of the most iconic things about the Joker is his laugh - indeed, it is such a haunting and distinct noise that Batman has a rule that there is no laughing allowed in the Batcave. Gotham's citizens have all heard Joker's laugh at one point or another, which is why this super-power is one of the most dangerous Joker has ever gotten. In Batman/Judge Dredd: Die Laughing by Alan Grant, John Wagner, and Jim Murray, the Joker manages to escape to the Judge Dredd universe after stealing a multiversal teleportation belt.
Joker encounters Judge Death - the one villain who may actually be more twisted than the Jester of Genocide. Judge Death sees all life as a crime, and works with a gang of zombified killers to eradicate all life on Earth, just as he did in his own home dimension. Death welcomes Joker into the gang, making him immune to injury (since he's technically a ghost possessing a dead body), and giving his laughter the power to explode the heads of anyone who hears it. It's a dark, gory power that's a little too extreme for DC's typical stories, but right at home in Judge Dredd's harsher reality.
2 Superman's Powers & Shapeshifting (The Mask)
Joker has tangled with the Man of Steel numerous times in comics, but in DC's crossover with The Mask, Joker gained the supernatural antihero's shapeshifting powers, and used them to turn himself into a rip-off Man of Steel. Readers got to see this in Joker/Mask by Henry Gilroy, Ronnie del Carmen, Howard Shum, and Ramon F. Bachs. When the Joker gets his hands on the iconic Mask, he is granted all the powers that usually come with that, such as invincibility and cartoon-level reality manipulation.
Joker enjoys his new powers, switching between looks before finally becoming "Super Joker." This killer identity is as fast and strong as a Kryptonian, with 'Haha' vision that turns his iconic laughter into a bizarre version of Superman's heat vision. Batman is only able to survive by pointing out that the mask is using Joker for its own goofy agenda, causing the Clown Prince of Crime to reject godlike power in favor of true freedom.
1 Reality Manipulation (Marvel)
While the Mask granted Joker reality manipulation on a cartoon level, such as access to concepts like Hammerspace, he gained true reality manipulation during the events of Batman vs The Incredible Hulk by Len Wein and José Luis García-López. During the events of this story, Joker is actually granted his godlike powers by the Marvel character the Shaper of Worlds. The Shaper of Worlds is a naive but benevolent God who wants to help make people's dreams come true. Unfortunately, he chooses Joker as the beneficiary of his gift, and Joker gains god-level reality manipulation. Joker very nearly destroyed the world with these powers, he was able to easily defeat both Batman and the Hulk and was only brought down by Batman attacking the Clown Prince of Crime's ego, resulting in Joker overloading and losing his powers.
The Joker is always changing - adjusting instantly to the circumstances around him, albeit solely in the interests of sowing as much chaos as possible. That's at its most extreme when the DC Universe crosses over with other media properties, showing that while the Joker may not have powers of his own, he's always looking for new weapons to use against Batman and Gotham, making him particularly deadly whenever the multiverse is involved.