|Appeared in||Batman: Under the Red Hood|
The Joker is hired by Ra's al Ghul to distract Batman and Jason Todd, the second Robin, from the terrorist's plan to destroy the world economy. The Joker lures the Dynamic Duo to Sarajevo, Bosnia, where he beats Jason with a crowbar and leaves him to be killed by a bomb. Feeling guilty for his death, Ra's al Ghul revives Jason with the Lazarus Pit. Years later, Jason returns to Gotham as a crime lord calling himself the Red Hood, purposely taking his murderer's former criminal identity to attract his attention. After his first encounter with the Red Hood, Batman goes to Joker for information in Arkham Asylum. He claims that there is no connection. When Red Hood tries to kill him, Black Mask hires the Joker as a hitman to take down the Red Hood. The Joker kidnaps Jason's eight under-bosses, including the Black Mask, and holds them hostage inside an oil tanker. Jason arrives and reveals that his previous actions were designed to lure the Joker away from the safety of Arkham so that he could kill him. Jason beats and kidnaps the Joker and brings him to Crime Alley. He forces Batman to either kill him or the Joker, or Jason will detonate a bomb killing all three of them. Refusing either offer, Batman allows Jason to detonate the bomb but saves himself, Jason and the Joker. While Jason escapes, Batman takes the Joker back to Arkham.
- Batman - Archenemy.
- Dick Grayson/Nightwing - Enemy.
- Jason Todd/Robin - Enemy.
- Red Hood - Enemy.
- Ra's al Ghul - Former ally.
- Black Mask - Former ally.