The Joker is a minor antagonist in Son of Batman, a cameo villain in Batman vs Robin and a supporting antagonist in Batman: Hush. He is the arch-nemesis of Batman and the boyfriend of Harley Quinn.
Son of Batman
When Batman went to visit Killer Croc, he and Jim Gordon passed the Joker's cell which shows his shadow and him laughing hysterically.
Batman vs Robin
The Joker is only seen in a photo on the Batcomputer when Batman is closing the case on the Dollmaker.
Suicide Squad: Hell to Pay
The Joker is only mentioned when Harley Quinn believes that she will go to heaven because anyone deserves a break from the Joker.
The Joker is one of a few villains that have been manipulated by Hush (who is secretly the Riddler trying to prove he is smarter than any other villain due to his lack of respect among the villains.) in a plot to kill Batman. During the robbery at the opera, Batman and Catwoman fight Harley Quinn and the Joker's goons. Batman hears a gunshot and sees that his childhood friend, Thomas Elliot, has been shot dead. Believing that the Joker is responsible for killing Elliot, Batman angrily beats up the Joker who enjoys it but while at the same time, tries to tell Batman that he is innocent and that he didn't kill Elliot. Batman refuses to listen to him and prepares to strangle him to death. Commissioner Gordon manages to stop Batman from killing the Joker and Batman leaves, horrified that he almost broke his code. The Joker asked who's Robin these days but only got punched by Gordon as the latter tells him to shut up. The Joker is then detained with double hand and leg cuffs and taken to prison while laughing hysterically. Later, after Batman and Gordon visit the "Riddler" who explains about becoming Hush, manipulating all the villains and finding out Batman's secret identity until Batman exposes him as Clayface who was being controlled by the Riddler and Batman gets into a fight with him. The Joker along with the other prisoners watch the fight to his satisfaction. The Joker taunts to Batman about "seeing" another villain and that he thought they had something "special". The Joker tells Batman to attack Clayface who just called him a "freak" and pretends to give up on Batman. After Batman frees himself from Clayface's grip, the Joker tells Gordon to get up and do something. Gordon fires at Clayface who just molds him into his body until Batman uses a host pipe to fill Clayface's body with water and explode much to the Joker's amusement.
The Joker like every other incarnation of him, is a sadistic, psychopathic madman who enjoys killing. While being beat up by Batman, he was enjoying it but was also trying to tell Batman that he was innocent. The Joker was starting to enjoy the moment of being strangled due to the fact that he has been trying to make Batman break his code.
- Batman: Hush is the Joker's first physical appearance while he only made cameos in the other films.