Carnage

Carnage was once a serial killer known as Cletus Kasady, and became Carnage after merging with the offspring of the alien symbiote called Venom during a prison breakout. The symbiote amplified his psychotic nature making him even less mentally stable than he had been previously, and therefore even more dangerous. An interesting note is that, unlike Venom, Carnage is a singular entity, referring to himself as "I" instead of "We", because the symbiote has actually merged into Kasady's bloodstream. Carnage is also the "father" of Toxin. A note on his childhood: Cletus' father killed his wife (Cletus' mother) because she tried to kill Cletus. Cletus then testified in court against him, saying that he killed her for no reason, causing him to die by electric chair as means of punishment. It is also unclear on Cletus' relationship with his mother, as he seems to have feelings for her, causing him to dig up her grave at the end of his massacre through New York. He also revealed that he killed his grandmother when he was younger, pushing her down a flight of stairs. Since the alien symbiote adapts to the host's personality, the Carnage symbiote is affected by Kasady's insane mind and lust for destruction.

Kasady has been separated and re-attached to the symbiote multiple times. The Carnage symbiote has occasionally attached itself to other hosts, including the Silver Surfer, Ben Reilly (a clone of Spider-Man), and Doctor Octopus. Venom later decided to absorb the Carnage symbiote "for good", during which Kasady retained the Carnage persona by costuming himself in red paint and continuing his killing sprees (albeit as a powerless human). This was short lived, however, as Kasady coincidentally found an exact replica of the symbiote in the Negative Zone. As to whether or not the symbiote is a separate entity, "permanently" bonded, or his own blood mutated, has not been revealed. The symbiote once chose to leave Kasady and bond with Ben Reilly. Kasady, without the symbiote, rapidly aged and his body quickly deteriorated. In this state, Kasady was barely able to function, having a hard time operating a sink, let alone being a threat. The symbiote bonded with him again in time to save his life, regenerating his health. When the symbiote abandoned him yet again, this time to join with the Silver Surfer(transforming him into the Carnage Cosmic), Kasady was left dying from an accelerated form of stomach cancer (apparently a side-effect of the symbiosis, also suffered by Eddie Brock, the original Venom). However, when Venom ate the symbiote, he did not deteriorate, indicating that perhaps some fragments of the symbiote were left behind (enough to sustain him but not enough to form the costume). This may be backed up by the fact that Kasady seemed to retain at least some enhanced strength.

Later, Venom and Spider-Man had to team up to stop Carnage. During this time it was revealed that the symbiote had become a part of Kasady's blood and was irremovable from him. Kasady only needed to be cut for the symbiote to flood out to become Carnage once again. Unlike Venom, Carnage had become less vulnerable to the high-pitched sounds which would normally stop Venom, however he was still vulnerable to intense heat.

Recently, Carnage was one of many super-villains trying to escape from the Raft. He tried to kill couple helpless civilians who were there to meet another inmate called Sentry. Who then intervened and flew Carnage outside of the Earth's atmosphere, where he ripped him apart. Kasady was presumably killed and has not been seen since.

As Eddie Brock explained, the Carnage symbiote was born with abilities even more singular than those of its progenitor due to the fact that it gestated in an environment alien to it-Earth. The alien symbiote endows Kasady with physical strength greater than that of Spider-Man and Venom combined and shape-shifting abilities, allows it to project a web-like substance from any part of his body including the formation of weapons, and enables it to plant thoughts into a person's head using a symbiote tendril. Much like Spider-Man, Kasady has the ability to cling to virtually any surface, and has a version of Spider-Man's spider-sense, as the symbiote can relay information to him from any angle and grants Kasady the ability to "see" in any direction, warning him of incoming threats. As a result, Kasady can rapidly crawl, walk, or run across even slick surfaces. The Carnage symbiote has abilities similar to those of Spider-Man as a direct result of the Venom symbiote bonding to Peter Parker, who transferred some of Spider-Man's power into the symbiote.

Kasady is able to regenerate damaged body tissues much faster and more extensively than that of an ordinary human. This has been shown as powerful enough to allow him to regenerate from losing any part of body, from head to feet. However, after being torn in half by the Sentry, he was fitted with artificial legs, but this occurred while he was separated from the symbiote.Kasady is also immune to the effects of all Earthly diseases and infections as long as he remains bonded with the symbiote. Like Venom, the symbiote is vulnerable to sound (to a much smaller degree than Venom) and heat (to a much larger degree than Venom), and is undetectable to Spider-Man's spider-sense. Unlike Venom, Carnage can launch parts of itself at enemies in the form of solid weapons such as darts, spears, knives, axes, etc., although they disintegrate into dust within ten seconds of leaving Carnage's body. Carnage also has the unique ability to warp its appendages into different arms, legs, and even wings. This is shown on several occasions when Carnage mutates fingers and arms into what look like large swords.

Kasady has full control over the size, shape, color (usually red and black), texture, and hardness of the symbiote (and any part thereof). Like Venom, he can make the symbiote look like normal clothing (which he has done on rare occasion), or act as "camouflage" to an extent. With the symbiote bonded to his bloodstream, he can "regenerate" his costume from scratch simply by bleeding. The symbiote has the peculiar ability to block its parent's (Venom's) ability to sense and track it. The symbiote is also able to rapidly adapt to new environments: when Kasady was taken into space by the Sentry, the symbiote was able to save his life by growing small sacks around his mouth that converted carbon dioxide into oxygen, allowing Kasady to stay alive long enough to be recovered.

In some interpretations, the Carnage symbiote is vampiric, feeding on and thus endangering its victims by only a mere touch. The symbiote has also shown the ability to call parts of itself back to the main symbiote, reintegrating them. It can also send irresistible commands to parts of itself that are in technology; these were used to break the bones of the Iron Rangers when they challenged Carnage while wearing symbiote-enhanced technological exo-suits. Using these last two abilities, Carnage absorbed the five Iron Rangers, grew to an enormous size, and became blue.

Finally, Carnage's powers have always been abnormally enhanced from the maniacal will and insane worldview that Kasady has had from the age of 8 years old. Kasady sees chaos and random, undirected violence as reality, and considers order and virtue to be illusions. He takes an almost artistic pride in his mayhem, likes to leave a trail for others to follow (usually leaving the phrase "Carnage Rules" written in his own blood), and is recklessly willing to take on the most dangerous and powerful opponents and victims. On rare occasions, however, he has deliberately spared individuals to serve as witnesses for others: for instance, Joe Robertson's wife Martha during Savage Rebirth. Kasady is essentially taking revenge on the whole world for the torments, both real and imagined, of his childhood.

When the Carnage symbiote was joined with Norman Osborn, the resulting combination was immune to traditional symbiote weaknesses of sound and fire, although Anti-Venom's touch was still dangerous.