The Joker is one of the Blind Bag characters in Lego Dimensions 2: The Rise of Enoch, from the Dark Knight Returns franchise.
Little is known about the early life of the Joker, save that he was a psychopathic serial killer. In one of his earliest recorded accounts, the Joker spent an evening in a hotel room with a reputable attorney named Donna Gugina. After a night of love-making, he brutally attacked her, crushing her larynx and strangling her to death. All the while however, he professed his undying love for her.
Well into his fifties, the Joker spent ten years at Arkham Asylum in a near catatonic stupor. When news hit the wire that his arch-nemesis the Batman had come out of retirement, the Joker's conscious mind resurfaced and he decided that it was time for him to come out of retirement as well. Having manipulated his psychiatrist into declaring him 'cured'- the doctor proclaiming that he was merely a victim of Batman's own psychosis- the Joker murdered the guests at a talk show where his psychiatrist had intended to publicly reveal his 'recovery' before taking hostages at a local carnival. Tracking the Joker there, Batman engaged his foe in the hall of mirrors before the fight progressed into a sewer, where Batman broke the Joker's neck just enough to paralyze him. However, in a last act of revenge against his enemy, the Joker was able to twist his neck just far enough to kill himself, committing suicide and framing his enemy for his own murder.