In 1988, Dennis O'Neil suggested that a telephone poll to determine the fate of the second Robin, Jason Todd in the four-part story "A Death in the Family". The verdict in favor of the character's death won by a slim 72-vote margin of 5,343 votes to 5,271.
The following issue, Batman #428, was published featuring Todd's death. Later O'Neil said "I heard it was one guy, who programmed his computer to dial the thumbs down number every ninety seconds for eight hours, who made the difference".
It was enough to see Jason Todd killed by crowbar at the hands of The Joker with Neil saying "It would be a really sleazy stunt to bring him back." The Joker then evaded capture by, well, becoming the Ambassador of Iran to the United Nations and gaining diplomatic immunity. As usual.
In September 2003, Jim Lee and Jeph Loeb's Batman storyline Hush suggested he was a resurrected Jason, revealed as a ruse by Clayface, but that Jason's body was still missing. Two years later, Judd Winick began the Under the Hood storyline that revolved around the mystery of the identity of the new Red Hood. The character's identity was revealed as Jason Todd in Batman #638. The explanation for the character's return was revealed in Batman Annual #25 in 2006.
That Todd had indeed died at the hands of the Joker. However, when Superboy-Prime altered reality from the paradise dimension in which he is trapped—his punches against the barrier keeping him from the rest of the universe causing temporal ripples.
Jason Todd is restored to life, breaks out of his coffin, and is eventually hospitalized; because he wandered so far from his grave before his discovery. After spending a year in a coma and subsequently another year as an amnesiac vagrant, he is taken by Talia al Ghul after a small-time crook recognizes him as Robin due to his combat skills on the street. Talia later restored Todd's health and memory by immersing him in a Lazarus Pit and helped him escape the House of al Ghul. It is suggested by Ra's that the power of the pit resulted in Todd's mental instability. Ra's refers to Todd as a "curse" and a "pestilence" unleashed on the planet, saying that madness may affect him for "hours, months, or decades".
He would become a gun-wielding vigilante, Red Hood, wearing the crowbar that killed him. The New 52 in 2011 remade him as Red Hood leading a team of Outlaws as well as his resurrection being simplified, killed by The Joker, then resurrected after he is placed into the Lazarus Pit by Talia al Ghul. It also changed the manner in which Batman first met Todd, now stealing medicine from Leslie Thompkins, after she had treated him from a brutal beating. The back-up introduces a massive retcon in which the Joker is responsible for orchestrating the major moments of Todd's life such as his father's imprisonment and death, his mother's overdose, his introduction to Thompkins and his adoption of the Robin identity, though that may suffer from an unreliable narrator in the Joker himself.
With DC Rebirth in 2016, courtesy of Geoff Johns and Gary Frank, his origin had also reverted to resemble his original meeting with Batman occurring while trying to steal tyres from the Batmobile.
Now in The Three Jokers, by Johns and Jason Fabok more has been rewritten. Specifically the supernatural or meta-ness of Jason Todd's revival
He never died. The Joker didn't kill him, but buried him in a shallow grave which he escaped from. Now how much of this "counts" in continuity is debatable, but The Three Jokers was mired in DC Comics continuity and this feels like the kind of thing that may be cherry-picked… Time to go back to the boards maybe? Jim Aparo prepared a long time ago.
The Three Jokers was published this week from DC Comics, by Geoff Johns and Jason Fabok.