Little is known about Karnevil. He was sent to Hell for his crimes, but was too much for them to handle. He even claimed that he taught the demons about torture during his stay. He later joined the Pentacle, as the counterpart to Detective Chimp. He captured and tortured Detective Chimp, but Chimp escaped. He then beat up and captured Karnevil who was subsequently sent to the Dark Tower.
Karnevil was one of the villains stranded on planet Salvation. He idolized the Joker. To prove that, he decided to be more like the Joker than the Joker. He planned to turn the Joker's skin into a cape. For a while he acted as the Joker's bodyguard, preventing Bolt from electrocuting him. When all the villains left the planet, the Joker insulted Karnevil, and left.
Kid Karnevil infiltrated the JSA, posing as the All-American Kid. He claimed that the original All-American Kid was a sidekick to Mr. America during WWII. He only briefly held the mantle, and was shot in the back soon after by a Nazi, leading for his contributions to the war effort to be all but forgotten. Karnevil pretended to be his grandson, Billy Armstrong, saying that he found a large amount of newspaper clippings and documents in his Grandmother's attic that contained all sorts of information on the original. Devoting himself to becoming the new All-American Kid, he trained hard to become a proficient gymnast of at least Olympic caliber.
Soon after, All-American Kid introduced himself to the current Mr. America, becoming his sidekick and joining the JSA in the process. Due to space constraints, All-American Kid was placed in a room with King Chimera. The two didn't get along, mainly due to Chimera's attitude. Karnevil stabbed Michael Holt, the second Mr. Terrific before hiding the crime. He pretended he had been mind-controlled, and that his mind was wiped to make him forget the incident. Jay Garrick, using his super speed to re-construct the security system, discovered Kid's actions and the JSA quickly levied accusations against him. He's since been taken into custody by the team. He escaped, hitting Mr. America over the head. He reveals that he was working for an unknown entity, and that his goal all along was to capture Obsidian, since the entity cannot touch him. Karvevil places Obsidian, who had been severely injured, into a device, completing his mission. However, he did not count on Mr. Terrific's recovery. Terrific reveals that he knew who All-American Kid really was. Karnevil acknowledges that Mr. Terrific is right, and prepares to attack him. Mr. Terrific knocks Karnevil out with his T-Spheres.
New 52: Earth 2 World's End
Karnevil works with John Constantine and his band of misfits for a brief time but when he shows discontent for Todd Rice aka Obsidian for being included in their plan of attack, Constantine empties his gun into Karnevil's head. Constantine then asks Brainwave Jr and Jonni Thunder (female version of Johnny Thunder) if they have a problem with Obsidian being included which inevitably they don't. Its possible that Obsidian and Constantine are lovers and Constantine felt insulted by Karnevil's remark towards Obsidian.
Powers and Abilities
Karnevil has no powers, but is a ruthless and sadistic killer. He is an expert in many kinds of torture.