Carnage

History
Cletus Kasady had a troubled childhood. He killed his grandmother by pushing her down a flight of stairs, and tortured his mother's dog. Afterward, his father apparently killed his mother, and received no defense from Kasady during his trial. As an orphan, Kasady was sent to the St. Estes Home for Boys, where his antisocial behavior made him the target of abuse from both the other orphans and the staff. Kasady gained revenge by murdering the disciplinarian administration, pushing a girl who refused a date with him in front of a bus and burning down the orphanage.

Homicidal maniac Cletus Kasady was serving eleven consecutive prison terms when an opportunity for early parole presented itself in the form of his new cell mate: Eddie Brock, human host to a symbiotic costume once worn by Peter Parker. Monster and man had merged to become the villainous Edward Brock Venom, but Brock was separated from the alien during a battle with the web-slinger. While Brock waited for the symbiote to spring him from prison, Kasady entertained him with his homicidal philosophy on life: Even the average person can commit murder, if only he has the courage.

As anticipated, the Venom symbiote attempted to free Brock by inciting a destructive jailbreak. Unknown to its human host, the alien was pregnant. It gave birth during the disastrous rescue. Left behind in the midst of the riot that ensued, the symbiote's spawn bonded with Kasady. Empowered far beyond the levels of Spider-Man and Venom, he made good his escape - intent on using his new-found power to disseminate his lethal doctrine and as Carnage, his first victim Gunther Stein was chosen from a Telephone book.

Embarking on a citywide killing spree, Carnage was confronted by Spider-Man. However, the wall-crawler's amazing arachnid-like abilities were insufficient to subdue the thrice-strong serial killer. Spider-Man was forced to enlist the aid of the Fantastic Four, the greatest team of superhuman adventurers ever assembled. He also sought the assistance of another, more dangerous ally: Venom, his hated foe. But the villain despised its offspring even more, and agreed to help. Facing the combined might of Spider-Man, Venom and the Fantastic Four, Carnage was captured and imprisoned at the Ravencroft Asylum.

Perhaps due in part to his insanity, Carnage's strength and abilities far exceed those of his predecessors, Venom and Spider-Man. Once, he even dispatched his symbiote through a phone line by reducing the alien to its cellular level. When an army of symbiotes invaded Earth, Carnage learned to feed on other aliens to increase his own mass. However formidable, almost all his bloodthirsty endeavors have culminated with his return to the Ravencroft Asylum, where the search continues for a cure to his homicidal tendencies.

After a battle with Venom, Carnage, was about to give birth to a another symbiote, he was threatened by its existence and attempted to destroy it. Venom, however, wanted to raise and train the new symbiote as an ally and partner. Weakened by the actual birthing, Carnage was unable to kill the newborn. Supplanting the symbiote in Patrick Mulligan, a New York City cop, it returned days. Venom named the new symbiote Toxin, after himself. Because they knew how powerful Toxin will be, and because his host is a cop, he would most likely be a good guy they made a temporally alliance, because they had to kill him, but in the end they were defeated.

Carnage met his fate when the Sentry ripped Carnage in half and flung him into low Earth orbit. According to Iron Man's computer, Kasady may not have been inside the symbiote when the Sentry ripped it apart.

Return
However, it is later discovered that while Kasady did in fact die in the incident, the symbiote survived by becoming dormant and returned to Earth. The Doppelganger and Shriek return, hoping to repair the symbiote[4]. Using the properties of the red symbiote, Michael Hall, a competitor of Tony Stark, creates prosthetic limbs and exo-suits which respond in the same ways as a symbiote. One such person, Dr. Tanis Nieves, is outfitted with one of these prosthetic arms after she is caught in an attack by Doppelganger. When near the red symbiote, her arm goes wild and forces her to kill several scientists before she is forcefully bonded, becoming the new Carnage. After the symbiote uses Tanis to break into a Hall Corporation facility, it is revealed that Cletus Kasady is alive, his body having been preserved by the symbiote and repaired by Hall's prosthetics.

Carnage battled Iron Man and Spider-Man upgraded with the "symbiotes" of Hall's super-guards. Then, Nieves' prothesis resulted to be a new spawn of Carnage, which turned her into a new symbiote called Scorn. Scorn obligated Shriek to use her sonic attack to debilitate Carnage, who later escaped with Doppelganger.

Cletus arrived to Doverton, Colorado and over took their poblation, controlling them with the Carnage Symbiote's copies, proclaiming this city the new capital of a new Symbiote sovereign state. Part of The Avengers, along with The Thing arrived to stop him, but were possessed by Carnage Symbiote's copies, letting Spider-Man the only hero standing, Spidey managed to get out from there with the help of the resistance of non-infected citizens.

When the Mercury Team along Scorn attacked the zone in search of Carnage, Spider-Man and the resistance appeared to help him. Venom appeared just in time to save Spider-Man's life from Cletus, but when Scorn used a sonic weapon to debond Carnage, she also affected Venom. Leaving Cletus against an invalid Flash Thompson.