Cletus Cortland Kasady is a deranged and sociopathic serial killer and mass murderer who has bonded with an alien symbiote to become the notorious super-villain Carnage.
Following a dark and disturbed childhood which culminated in him burning down an an orphanage, Cletus became a serial killer and was eventually convicted for eleven consecutive life sentences. Incarcerated at Ryker's Island Prison, Cletus eventually became cellmates with Eddie Brock. When the Venom symbiote returned to rescue Eddie, it left behind its asexually-produced offspring. The newborn symbiote bonded to Cletus and amalgamated with his blood, transforming him into the monstrous Carnage. Over the years, Carnage became a recurring enemy to Spider-Man, Deadpool, the Avengers, and most notably Venom. Notoriously, Carnage once led a group of other killers and monsters on a rampage across Manhattan.
When Cletus reentered Earth's atmosphere following the Poisons' invasion, Cletus and his symbiote-remnants perished, but a cult worshiping the symbiote god Knull bonded him to a new symbiote linked to him, reanimating Cletus and restoring the Carnage symbiote more powerful than ever. Cletus intended to free Knull, succeeding when Eddie killed him and assimilated the codexes into a amalgam symbiote, later pilloting the Carnage symbiote. Cletus tried to overthrow Eddie when he became the new King in Black. Absorbing Iron Man's Extrembiote, Cletus and the symbiote eventually had a falling out, the serial killer expunging it from the Extrembiote. The Carnage symbiote eventually created a clone of Cletus in order to direct it in its ascension. Somehow restored to human form but severely weakened, Cletus tried to confront them both by imbuing himself with antibodies in emulation of Anti-Venom, but had his brain devoured, the clone absorbing his memories and consciousness in the process to become one.
