Film
Live action
- Along with The Dark Knight Returns, Tim Burton has mentioned that The Killing Joke influenced his film adaptation of Batman, specifically the origin of the Joker: "I was never a giant comic book fan, but I've always loved the image of Batman and the Joker. The reason I've never been a comic book fan — and I think it started when I was a child — is because I could never tell which box I was supposed to read. I don't know if it was dyslexia or whatever, but that's why I loved The Killing Joke, because for the first time I could tell which one to read. It's my favorite. It's the first comic I've ever loved. And the success of those graphic novels made our ideas more acceptable".[20]
- Director Christopher Nolan has mentioned that The Killing Joke influenced the story, themes and Heath Ledger's performance as the Joker in the 2008 film The Dark Knight. The Joker's ambiguous, multiple-choice past and depiction as an unreliable narrator who provides various alternate possibilities of his origins, was inspired by the comic, as was the character's line "Madness is like gravity. All it takes is a little push", a nod to the Joker's philosophy in The Killing Joke that "All it takes is one bad day to reduce the sanest man alive to lunacy". In both stories, the Joker tries to corrupt one of Batman's allies by harming their loved ones. Ledger also stated in an interview that he was given a copy of the graphic novel as reference for the role.[21]
- Writer/director Todd Phillips said that the Joker's descent into madness after an unsuccessful career as a stand-up comedian, his past as a struggling lower-class citizen, and his ambiguous past in The Killing Joke served as an inspiration for the narrative and thematic elements of the 2019 feature film Joker.[22]
Animation
- The story is referenced in a flashback scene in the DC Universe Animated Original Movie, Batman: Under the Red Hood. Red Hood lures Batman (voiced by Bruce Greenwood) to the chemical factory where the Joker's (voiced by John DiMaggio) accident took place. The flashback then shows a fleeing Joker had attempted to escape while trying to claim that he was set up, only to accidentally fall into the chemicals that disfigure him. The film's villain, Jason Todd (voiced by Jensen Ackles) – whom the Joker had murdered, and who takes up his murderer's former criminal identity upon being returned to life by Ra's al Ghul (voiced by Jason Isaacs) – calls it Batman's greatest failure. Jason also obliquely refers to the Joker crippling Barbara.[23]
- Batman: The Killing Joke animated film was released on Blu-ray and DVD on August 2, 2016, and also played in select theaters in July. Sam Liu directed and Bruce Timm executive produced the film. The Batman: The Animated Series castmates, Kevin Conroy, Mark Hamill, and Tara Strong returned as Batman, the Joker, and Batgirl, respectively, alongside Ray Wise as Commissioner Gordon.[24] The film received a mixed reception.[25] The film's storyline follows the original comic, but also includes a new storyline involving Barbara's decision to retire as Batgirl after a crisis involving a Mafia war, as well as a brief sexual relationship between Batman and Batgirl that earned a particular amount of criticism from critics and fans.[26]
- The Killing Joke was referenced several times in the interactive film adaptation of Batman: Death in the Family, which serves as a follow-up to Batman: Under the Red Hood. The film also reused the pictures the Joker took of Barbara in The Killing Joke animated film. If Batman sacrifices himself to save Jason, two possible scenarios can play out. If Jason chooses to disobey Bruce's dying wish, he meets the Joker at a diner. Joker reminisces about Batman by retelling Jason the same joke he told Bruce at the end of The Killing Joke before Jason stabs him to death. If Jason attempts to uphold Batman's moral code and arrest Joker without killing him, Joker reveals to him that he has been repressing all the times he killed criminals during his time as the Red Hood and has become more of a successor to the villain himself rather than Batman – all because of "one bad day".
Television
- In the pilot episode of the 2002 Birds of Prey television series, the pilot episode includes a version of the scene in which the Joker shoots Barbara in the spine, paralyzing her.
- In the FOX TV series Gotham (2014–19), story arcs involving the show's "Proto-Jokers",[27] Jerome and Jeremiah Valeska (both played by Cameron Monaghan), are heavily influenced by The Killing Joke. Several scenes, themes, and lines of dialogue are directly taken from the comic. The episode "A Dark Knight: One Bad Day" takes inspiration from the Joker's observation that "All it takes is one bad day to reduce the sanest man alive to lunacy", and ends with Jeremiah shooting and paralyzing Selina Kyle (Camren Bicondova).[28]
- In Young Justice, Barbara Gordon/Batgirl (voiced by Alyson Stoner) is introduced in Season 2, but is shown to become Oracle in Season 3 during the two-year time skip between seasons. In Season 4, it is revealed that Barbara was paralyzed after saving the Joker from an assassination attempt by Cassandra Cain. However, Barbara tells Cassandra she did not save the Joker for his sake, but to prevent Cassandra from becoming a killer.[29]
- In Harley Quinn, the Joker shoots Batgirl when Harley Quinn meets with her to tell her that she's quitting the Bat-family at the end of "A Potato-Based Cloning Incident." In "Killer's Block," it's revealed that Batgirl is paralyzed from the waist down as Harley tortures the Joker for revenge, with Joker revealing he shot Batgirl after she exposed him for not being the one to kill Nightwing.
Video games
- In the 2008 video game Lego Batman: The Video Game, there is an alt featured in the game for The Joker called The Joker (Tropical), which shows him wearing a Hawaiian shirt, purple gloves and a sunhat, which looks very similar to the scene when he shoots and cripples Barbara Gordon in The Killing Joke, albeit with a few changes.
- In the 2011 video game Batman: Arkham City, the Joker (again voiced by Hamill) recounts his backstory from The Killing Joke to Hugo Strange (voiced by Corey Burton). When Strange expresses doubt at the Joker's story, the Joker admits that he prefers his origin story "to be multiple choice", repeating the line from the graphic novel.
- In the 2013 video game Injustice: Gods Among Us, a downloadable content Killing Joke pack includes three skins for the character from the story. It includes his Hawaiian attire, the Red Hood, and his hat and long coat.
- The 2013 video game prequel Batman: Arkham Origins, makes several references to The Killing Joke. When Batman (voiced by Roger Craig Smith) enters a carnival-themed room, the Joker (voiced by Troy Baker) tells him he got a great deal on an out-of-service amusement park, and jokes that "You should have seen the look on the real estate agent's face when we shook hands on the deal!", an allusion to the scene early in the graphic novel in which Joker cons the owner of a run-down amusement park out of the property, and then murders him. In a level depicting a psychiatric interview with Dr. Harleen Quinzel (voiced by Tara Strong), Joker is playable as the Red Hood, walking through the chemical plant that will end with his transformation into the Joker. Another scene shows him in an altercation with patrons at a comedy club who exhibited a poor reception to his act. Baker recites a monologue from the graphic novel.[30]
- The 2015 video game Batman: Arkham Knight depicts the Joker's shooting of Barbara Gordon as one of the hallucinations Batman experiences.[31]
Novel
Novelists Christa Faust and Gary Phillips wrote a novel adaptation of Alan Moore's story, published on September 25, 2018, by Titan Books.[32]
Miscellaneous
One of the two covers of the comic book Darkwing Duck Annual, published in March 2011, was a homage to Brian Bolland's cover of The Killing Joke.[33]
