Carnage is a creature of the alien entity Klyntar symbiote, which linked to failed journalist Eddie Brock form the villainous Venom. When Eddie Brock was arrested, his cellmate was Cletus Kassady, a vicious psychopath, and serial killer, and when the alien symbiote entity rejoined Brock in prison, his escape left a fragment that proved to be a symbiotic offspring which reproduces asexually.

The newborn creature merged with Cletus, and it was from this union that the Carnage arose that began his career of meaningless homicides or criterion of choice of victims, where the villain justifies his actions with an absurd philosophy that he essentially calls Katia chaotic and that law and order are perversions.