Judge Giant can refer to either of two fictional characters appearing in the Judge Dredd comic strip in 2000 AD. They are father and son. Their first names have never been given.
They are both descended from another 2000 AD character, 'Giant' (real name John Clay), who starred in his own series in 2000 AD, Harlem Heroes, which ran in progs (issues) 1–27 of the comic. John 'Giant' Clay made a cameo appearance in the Judge Dredd strip in prog 28. Since Judge Dredd himself did not appear in 2000 AD until prog 2, the Giant family's appearance in the comic predates Dredd's debut in his own strip.
Judge Dredd writer Al Ewing has explained the appeal of the second Giant as "he’s Dredd’s successor, except he’s human in a way Dredd isn’t... So there’s a wealth of story potential there".
The original Judge Giant first appeared in prog 27 of the comic (1977) as a rookie judge who had just graduated from the Academy of Law. Set in 2099, his first appearance in "The Academy of Law" (progs 27–28) was a crossover with Harlem Heroes, set decades after the events depicted in that series. It featured a cameo appearance by his father, John 'Giant' Clay, as a very old man at the end of the story. "The Academy of Law" is also notable for the debut of another important supporting character, Judge Griffin, as well as the Academy of Law itself. It tells of Rookie Giant's Final Assessment, a gruelling test of his judgement and abilities to determine his suitability for promotion to full judge. His supervisor is Judge Dredd, who passes him.
Judge Giant became Dredd's sidekick for the next four years. His most important story was the 23-episode Judge Cal storyline, in which he first saved Dredd from being executed and then fought with him against Cal's renegade judges and alien mercenaries until the end. Although he had an important role in that story, his appearances in later tales were generally little more than mere cameos, and his importance within the strip tailed off somewhat. He was finally killed off in the "Block Mania" story (1981) while trying to arrest Orlok just before the Apocalypse War. The unheroic circumstances of his death (he was shot in the back in a brief scene) were controversial among fans, since although they were used to seeing popular characters killed off in 2000 AD, they were disappointed with the cursory way in which Giant's death was depicted. In an interview years later, writer Alan Grant said: "When we wrote the death of Giant, I thought it was a great idea to kill him off in such a casual, natural (for a judge) way. But when the reader outcry came, I was startled and forced to see things from their point of view."
An evil version of Judge Giant from a parallel universe, where he still lived and had killed Dredd for Cal, appeared in the story "Helter Skelter" (2001). Dredd killed him with ease.
In 1989 the story "Young Giant" established that the original Judge Giant had fathered a child in 2101, something prohibited to judges. Orphaned when his mother was murdered in front of him shortly after the Apocalypse War in 2104, Giant's son had been inducted into the Academy of Law, where he performed extremely well but with a worrying streak of violence that threatened his ability as a judge. With Dredd's help, Giant was able to get past his deep-rooted anger and brought his mother's killer to justice.
Unlike his father, who became a full judge in his first story, Cadet Giant remained a cadet for five years during his recurring appearances in the strip. He was a major protagonist in one of Judge Dredd's biggest and most significant epics, "Necropolis", even taking over the lead role from Dredd himself in half a dozen episodes (including two in which Dredd did not even appear). He led a group of cadets who remained free of Dark Judge control and, at one point, were personally hunted down by Judge Mortis. He would later be one of the first people to battle Sabbat's zombies during Judgement Day. Eventually he became the youngest cadet ever to graduate from the Academy, at the age of fifteen, having been fast-tracked. In a story reminiscent of his father's debut, Giant's Final Assessment was conducted by Judge Dredd, who passed him as fit to become a judge in 2116.
The new Judge Giant has made several appearances since, and actually saved the whole world from a deadly virus in 2117. He is apparently one of the best judges in Mega-City One, although he has not featured in any story to the extent that he did in "Necropolis". Dredd has often turned to him for back-up and assistance, being part of a covert team behind Sov lines, investigating a deadly assassin, carrying out a command role in the Ciudad Barranquilla peacekeeping/regime change mission in 2128, and playing a key role in defending the Grand Hall of Justice against the alien Incubus. When he first met Judge Rico, Dredd's clone, in 2126, Rico told him that Dredd had called him the best back-up man in the department and that every cadet at the Academy of Law had tried to beat Giant's cadet scores (Rico had beaten all of them). He became used to having strong control over the operations he ran; for a brief period under Chief Judge Sinfield, however, he lost these privileges and was forced to work for the incompetent Judge Oldham (who Giant was senior to) as a deliberate snub.
In a six-page one-off story in the Judge Dredd Megazine #216 called "Whatever Happened to John 'Giant' Clay?" (2004), Judge Giant met his grandfather for the first time. The original Giant had not appeared in any story since 1978, and this story ended with his death from old age. In the same issue, Judge Giant was the lead figure in the Judge Dredd strip and first teamed up with Dredd's clone, Judge Rico. In that Megazine issue (set in 2126) Rico remarked that they make a natural duo. Giant was initially bothered by the existence of Rico: he had known that Dredd had been grooming him as a possible replacement and the existence of 'another' Dredd ended that. Despite that, the two became friends during their first meeting, and since worked together on other jobs. After their first meeting Giant said he would be available if Rico needed someone to talk to when Dredd was not available.
Giant has also, on three occasions, aided judges in trouble: he helped a severely wounded and despondent Judge Guthrie recover the will to live, he turned around a troubled cadet called Danzer, and worked with Oldham to make him a better judge (this last attempt failed).
Giant was shot and severely wounded during the 2011 story "Served Cold." However he has since returned to street duty.