A twisted creature from another dimension, Judge Death reasoned that since all crime was committed by the living, life itself was unlawful, and he set out to destroy all existence. Once a young boy called Sidney De'Ath, the warped son of a dentist, who torture his patients and would sometimes kill them, Sidney grew up admiring his father's work saying it had a prolonged affect on him.
As he grew up, torture was not enough and he wanted to bring justice to his world and the only way possible was by becoming a Judge. On the day of his graduation his mother and sister left, hoping to run away, but Sidney found them and tortured and killed them. The turning point for Sydney was discovering the Sisters of Death (two witches called Phobia and Nausia). With their help he became the undead monster Judge Death, before repeating the procedure on three other Judges. They became Judge Fear, Fire and Mortis - The Dark Judges.
Together they exterminated all life on their planet and renamed it Deadworld. When an dimensional traveler accidentally stumbled on Deadworld, Death killed him and took the technology for the Dark Judges. With it, he reasoned, they could eradicate life across other worlds and dimensions.
They started with Mega-City One.
John Wagner and Brian Bolland are responsible for creating the character of Judge Death. His first appearance is in 2000 AD #149.
Major Story Arcs
Judge Dredd and Mega-City One
Judge Death's first battle with Judge Dredd did not go well. His body was destroyed and his spirit possessed Judge Anderson. Dredd's only hope of stopping him was to encase Anderson in Boing (a hard gelatinous substance). The other Dark Judges crossed over and set Death free. Together they slaughtered thousands of citizens and it took the combined skill of Dredd and Anderson (still alive, and removed from the Boing, once Death had left her body) to stop them. Over the years, the Dark Judges have returned, but have always been defeated by Dredd or Anderson. Eventually the Sisters of Death, now spectral beings, arrived in Mega-City One and along with the Dark Judges, enslaved the Mega-City Judges, conquering the city and created their Necropolis - a horror that took the lives of 60 million people.
The Cursed Earth
The end for Death came when he went out into the Cursed Earth. Deciding that killing people one at a time wasn't enough, he came across an old bunker full of nuclear weapons. Using this he destroyed Las Vegas and tried to destroy Mega-City One, but was stopped by the city's anti-missile system. The Judges, believing it was just an old bunker becoming active, fired missiles at the location, destroying Death's body and releasing his spirit into the astral plane. Here he was attacked by a man whose family he had killed when he first entered the Cursed Earth and had now become an angel. The angel beat Death to the ground then opened a pit leading straight to hell. Death was then dragged into Hell by the vengeful ghosts of all those he had killed...