|Home Realm:||Gotham City (DCU Dimension)|
|First Appearence:||Mortal Kombat vs. DC Universe|
The Joker is a villain in DC Universe, first shown and primarily appearing in Batman comics, known as 'The Clown Prince of Crime' , 'The Harlquin of Hate' and 'The Ace of Knaves' . He is an insane super-villain whose only real aim is to fight Batman and have fun doing it. He uses comical weapons, such as a flower which squirts acid, razor sharp playing cards and an electric buzzer with a lethal voltage level, and something called Joker Venom. Joker Venom is a type of gas/liquid which causes the victim to grin widely and, quite literally, laugh themselves to death.
The past of The Joker is, and quite possibly always will be, unconfirmed. He himself has told many versions of his past and in the graphic novel, The Killing Joke, he said to Batman 'I'm not exactly sure what happened. Sometimes I remember it one way, sometimes another... If I'm going to have a past, I prefer it to be multiple choice!'. DC haven't ever confirmed one story over another, possibly liking the addition of mystery to the character, but three versions of The Joker's past are more commonly known and accepted.
One involves him being a mafia crime-boss, another has him as a scientist and the third tells that The Joker was once a struggling stand-up comedian trying to support his pregnant wife and unborn child. All three accounts end in his first encounter with Batman while he was acting in the identity of 'The Red Hood' with a gang of other thugs, committing a robbery in the Ace Chemical Processing Plant. He either trips into a vat of chemicals or is accidentally pushed in by Batman. After, he emerges from a nearby reservoir driven totally insane by a combination of exposure to the chemicals and possible brain damage due to oxygen deprivation. His skin is chalk-white, his lips ruby-red and his hair bright-green. Upon seeing his reflection he starts laughing maniacally, from that day continuing as the insane super-villain, The Joker.
Although not having any super-powers, it is speculated he has a very high threshold to pain as a result of his exposure to chemicals. This theory is backed-up by the fact he laughs whenever being beaten, even mocking his opponent ( '(As Nightwing pummels him) "Aw... Jeez... I hit Jason a lot harder than that. *Pause* His name was Jason, right?"' ). It is also speculated that The Joker may be immortal due to the fact he has cheated death many times, emerging alive from plane crashes, explosions, electrocutions, falling from great heights and other major incidents. Neither of these theories have been confirmed however.
The Joker does have the intellect of a genius, however, being able to create all manor of comedic weapon to battle Batman with. He is also very highly skilled in the fields of chemistry, genetics and nuclear engineering. It has been said that The Joker has a sort of 'super-sanity' which allows him to re-create his personality to cope with day to day life. One day he'll be a harmless clown, luring Batman into a trap, tying him up and then shooting him with a squirt gun just for fun, and another he'll be a psychotic criminal, murdering, stealing and hurting as he sees fit.
- 'Unlike you and I, the Joker seems to have no control over the sensory information he's receiving from the outside world. He can only cope with the chaotic barrage of input by going with the flow. That's why some days he's a mischievous clown, others a psychopathic killer. He has no real personality. He creates himself each day. He sees himself as the Lord of Misrule, and the world as a theater of the absurd.'
- Dr. Adams, Joker's therapist while he was in Arkham Asylum (Gotham City's insane asylum)
 The Joker in Mortal Kombat vs. DC Universe
The Joker is one of the few DCU villains in MK vs. DCU. As would be expected of 'The Clown Prince of Crime' a lot of his attacks are comical, for example in one special attack he uses an extend-able boxing glove to punch the opponent. His fatalities are equally as comical, both using one of The Joker's signature 'toys' .
The first fatality happens as so (spoilers): The dazed opponent rocks back and forth as The Joker laughs maniacally, before he pulls out a gun and aims it at the opponents head. When he pulls the trigger, however, the gun is shown to be a joke weapon, showering the opponent in confetti as a small pole comes out of it with the word 'bang' written on a flag attached to it. The opponent breathes a sigh of relief, looking the other way, before turning back to The Joker. At this point The Joker has dropped the fake gun and pulled out a real one, swiftly shooting his victim in the head and proceeding to laugh in typical Joker fashion. Making use of his 'fourth-wall awareness' (in most portrayals The Joker has known where he is (whether in a comic, cartoon or video-game) and has acted accordingly (acting as if he's turning a comic book page for the reader, whistling his own theme tune, etc.). This is known as breaking the fourth-wall, when a character knows their reality is fiction and acts as such.), The Joker bows to the screen and players before striking a mocking, false-courteous pose.
Although not pertaining to the actual 'false 'bang' gun' (in the comics the gun would shoot with the 'bang flag' and then, when the trigger was pulled again, the flag and the pole attached to it would shoot at the victim, stabbing them with the pointed end) the fatality was very well received by Mortal Kombat and DC Universe fans alike.
The second fatality (more spoilers) shows The Joker pull out some playing cards. He then turns to the opponent and throws four cards at them in the style of a magician. Two hit and stick into the opponents stomach while the other two hit and stick into their shoulders. With a final flick, The Joker throws a card into the opponents forehead, leaving them to fall backwards, now dead. Once more The Joker bows to the screen before striking a pose of a magician as if to say 'ta-da!'
 Mortal Kombat VS. DC Universe
After Superman defeats Darkseid and saves Metropolis. Most of the world believe that the invasion is finally over, not knowing that there's a new crisis that's about to begin. The Joker was roaming around Gotham City when he encounters Scorpion as the spectre asks about Kitana, but The Joker gives Scorpion the run around and then uses a weird gun with a boxing glove to instigate Scorpion who fights and defeats The Joker. After the fight, The Joker is founded by Lex Luthor, Catwoman and Deathstroke to solve this universal crisis. Then, they venture to Metropolis where they meet Superman and Captain Marvel after they talk about the universal crisis and a violent energy called "Kombat Rage". Luthor tells both The Joker and Deathstroke to infiltrate the base of the Outerworld Investigation Agency and find their teleportal. In a graveyard they encounter Sonya and Kano, The Joker uses his venomous flower to damage Sonya's wrist portal and were transported to OA. The Joker fights Sonya while Kano fights Deathstroke. During his fight with Sonya he becomes effected by Kombat Rage and becomes more insane, he pushes Deathstroke aside to fight Kano and defeats him. As Deathstroke repairs Sonya's wrist portal, they transport back to the graveyard where The Joker still under the influence of Kombat Rage turns against and defeats Deathstroke. Believing to be unstoppable, he goes back to Gotham City in hopes to defeat Batman. Though he fights Batman and has him pinned down, but Batman defeats The Joker by tazzing him and purge him from the Kombat Rage. The Joker is taken to the O.I.A. with the rest of the DC warriors use the teleportal in hopes to venture to Apokolips, they meet the rest of the Mortal Kombat warriors and fight them while under the influence of the Kombat Rage. The Joker would be defeated in this battle.