A character in the
Marvel Comics universe. Cletus Kasady, the
human half of Carnage, first appeared in Amazing
Spider-Man #345, and Carnage himself first appeared in Amazing
Spider-Man #360.
Cletus Kasady probably killed his parents in a fire that sent him to an orphanage, but this has only been implied. Once at the orphanage, he was bullied mercilessly and abused by the caretakers. After all of that, he grew up to be a serial killer. He was serving multiple life sentences when he met up with Eddie Brock (aka Venom). They were cellmates while Eddie's symbiote seemed to be dead. When it broke him out of prison, it left behind its spawn, which Kasady found and bonded with.
Since this symbiote was spawned on Earth, it has slightly different abilities than Venom's. Carnage is stronger and faster than Venom. He doesn't set off Spider-Man's spider-sense, an ability that the symbiote inherited from the Venom symbiote. He is also able to shoot projectiles made of his symbiote, which are generally pointy things. He has a weakness to fire and such, but not to sonics, like Venom.
Using his symbiote, Kasady racked up a kill count in the hundreds. He was responsible for the 'Maximum Carnage' storyline, where he teamed up with four other bad guys to wreak havoc. They rampaged through New York City, killing dozens and setting off riots. Carnage was stopped and sent to Ravencroft, a maximum security mental hospital, where he was kept using microwaves. His symbiote could not be seperated from him because it became a part of his bloodstream. When he escaped, he was put in a silver shell of energy by the Silver Surfer, which he has since gotten out of.
Venom came and absorbed the Carnage symbiote while Kasady was imprisoned once again in Ravencroft. He also took out all the guards, allowing Cletus to escape again. Kasady is still at large, which is surprising, because it was revealed that he has an advanced case of stomach cancer that his symbiote keeps in check. Since he currently does not have the symbiote, you would think he would die. That's comics for you.