- Real Name: Jeremy Karne
- Alias: All-American Kid, Karnevil, Kid Karnevil, William Armstrong
- Identity: Secret
- Alignment: Bad
- Gender: Male
- Hair: Blond, Eyes: Unknown
- Occupation: Professional criminal
- First appearance: Shadowpact #1 (July, 2006)
Very little is known about the origins of the mysterious being known as Karnevil. Rumor has it that he once died and went to Hell for his sins, but was kicked out because he "scared the staff", in his own words. His sociopathic tendencies eventually brought him to the attention of Strega, leader of a mystical cabal known as the Pentacle. Although she found him monstrous, she invited him to join her team. The Pentacle targeted the small town of Riverrock, Wyoming to stage a massive necromancy ritual designed to summon the essence of the Sun King. Their actions earned them the attention of the Shadowpact. Karnevil had little interest in Strega or her ambitions, and was content with the ability to sew discord at any given opportunity. While the other Pentacle members fought against the rest of the Shadowpact, Karnevil set his sights on Detective Chimp. He captured the simian and chained him up with plans of torturing and eventually murdering him. Karnevil didn't count on Detective Chimp's enhanced strength however, and he broke free of his chains and beat Karnevil into submission. He left the psychotic youth tied to a tree, while he rejoined his friends. At the conclusion of the Riverrock affair, all of the members of the Pentacle were captured and placed in custody.
Karnevil was one of many super-villains exiled to the planet known as Salvation. It is here on this planet that Karnevil admits to the Joker that he has been looking him up as a role model, but he swore to him that he will surpass his notorious status by killing him in the most gruesome way. Joker, however, nonchalantly respond to Kid Karnevil's threat with less concern stating that "many have tried. None have succeeded". Once Lex Luthor successfully builds a Boom Tube into allowing the villains to leave the planet, Karnevil was slapped across the face by Joker for being a "copycat".
Soon after Stargirl's 18th birthday, Kid Karevil joined the Justice Society, posing as the grand-nephew of "All-American Kid", the sidekick of the original Mister America. As a member of the team, he crippled Obsidian and Mister Terrific, inadvertently causing the destruction of the JSA brownstone by an army of mercenary criminals. He handed over the remains of Obsidian to an operative for the Fourth Reich, Shadow of War, who seek to use it to power a device which saps superhuman powers. The Justice Society were at a loss to deal with him, since he has no fear of death.
When the JSA planned to hand Jeremy over to the authorities, the Fourth Reich instantly attacked the JSA. It was revealed that The Fourth Reich wanted Obsidian to use him as the power source for their Darkness Engine, a machine that negated all super powers, which they activated during the attack on the JSA, which they activated during the attack on the JSA. A time jump then took place, revealing that twenty years into the future the Meta-population had been decimated, with the survivors being held in concentration camps. Jeremy, as an adult, was the Führer of The Fourth Reich. As part of Mr. Terrific's plan, he and the other former heroes struck out a war against the Nazis, in order for Mr. Terrific to get to the Darkness Engine and shut it down. However, when he made his way to the Darkness Engine, he decided to make a call to his past self and intervene The Fourth Reich's plan from the beginning.
When he made the call, it was just before he was about to be pronounced dead when Jeremy stabbed him. The injured Mr. Terrific blurted out how to hatch Obsidian, who was still in his egg form. When Green Lantern hatched him and by the time the Brownstone was attacked, Jeremy was looking for the supposed imprisoned Obsidian. But only to be surprisingly confronted by the said hero and was knocked out by Obsidian. Jeremy was later arrested along with the Fourth Reich, who were likewise easily defeated by the JSA thanks to Mr. Terrific's knowledge of the bleak future.