When a symbiote offspring of Eddie Brock (Venom), merges with serial killer Cletus Kasady, the result is the nightmarish murdering menace known as Carnage! Reborn from an alien creature, he’s a more psychotic and dangerous being that spawns a family of symbiotes. Born in Ravencroft Institute to inmate Louise Kasady, Cletus emerges into the world, perishes at birth, and ends up in hell where he’s caged. It’s there where Cletus’ devotion to chaos and death forms. Then, inexplicably revived, Cletus grows up to become a killer, though in his mind, he sets his victims free. Carnage made its first full appearance in The Amazing Spider-Man #361 (April 1992).

Sentenced to eleven consecutive life terms for the slaughter of numerous innocents, psychopathic serial killer Kasady shares time with his new cellmate, Eddie Brock. Brock had become separated from his symbiotic other half, Venom. The creature finds Brock in his jail cell and bonds with its host once more. The pair easily smash through the cell wall and vanish into the night, failing to notice the trace of alien biomass they left behind. The symbiote that had possessed Brock—and, at one time, Peter Parker (Spider-Man)—belonged to a less-violent caste of a bloodthirsty race of space-faring parasites. Quickly setting about to consume a host, the biomass melds with the murderous Kasady—and the deadly symbiotic duo calling itself Carnage emerges. Far more lethal than Venom, Carnage escapes jail to embark on a murderous spree, killing a graduate student at Empire State University (ESU) who happens to be friends with Peter, kicking off a long-term enemy in the wall-crawler.