While many of Venom's children have been known to be sadistic killers, some turned their life around and became heroes. But Carnage, venom's 999th offspring, is the one exception. On every version of Earth in the Marvel Multiverse, Carnage has always been a killer.
When bonded to Cledus Kasidy, Carnage is at his most dangerous, since both have acknowledged that they enjoy killing, as well as several other acts of sadism. They have found to be such a perfect match for each other, that the symbiote has bonded at the molecular level with Kasidy's DNA, allowing Kasidy to summon it even after it has been removed from him, as long as Kasidy can expose his blood to the open-air. Together, they've committed some of the most heinous acts in the Marvel Universe, in certain cases crossing a line, most villains wouldn't' dare.
10 Killed Gwen Stacy By Absorbing Her Life-Force
Earth-1610, also known as the Ultimate Marvel Universe, is an alternate timeline that hosts different versions of the Earth-Prime universe. In the Ultimate Universe, Carnage is the result of Dr. Curt Connors experimenting with Peter Parker's blood and the Venom symbiote. The resulting symbiote was vampiric in nature, able to create a humanoid-like body without a host, it survived by absorbing the life-forces of other humans. It is this Earth's Carnage that murdered Gwen Stacy, stealing her life-force and likeness in the process.
9 Cured The Joker Of His Sanity
During the one-time crossover Spider-Man and Batman: Disordered Minds, Joker is taken to the Ravencroft Institute to be part of an experimental procedure that would cure his insanity using a microchip that is implanted into his brain. The procedure is a success, curing Joker of his insanity. When they attempt to do the same procedure on Cleetus Kasidy, Kasidy uses the Carnage Symbiote, with whom he is bonded at the molecular level, to escape with a now sane Joker. He uses his symbiote Make the Joker insane again and the two join forces to plot a scheme against Batman and Spider-Man.
8 Turned An Entire Town Into Carnage Doppelgangers
After surviving being ripped in half by the Sentry, Cleetus Kasidy acquired a pair of robotic legs and emerged with the Carnage symbiote. The symbiote then led Kasidy to Dover, CO, where they slowly began infecting everyone in the town with copies of the symbiote, turning everyone from women to children into Carnage Doppelgangers. This was part of an attempt by Kasidy and the Symbiote to create a nation of symbiote's, composed entirely of Carnages. In the process, they infected the Avengers and the Thing.
7 Agreed To Bond With Norman Osborn
When Norman Osborn acquired the Carnage symbiote from Cletus Kasidy, he bonded to it hoping to gain an edge against Peter Parker. The symbiote, reluctant to bonding with Osborn, was convinced to agree after Osborn told him he could show it new ways to commit pain. In the process, the two became the sadistic Red Goblin and were able to gain the upper hand in defeating Spider-Man.
Although Osborn ripped the symbiote off near the end of the battle after Spider-Man convinced him Kasidy would receive credits for Spider-Man's death, the Carnage symbiote implanted a copy of Kasidy's memories inside Osborn, making him believe he was Kasidy as revenge for betraying him.
6 Infected All The Homeless In San Francisco With Brain Worms
After being brought back to life by the Church of the New Darkness, a cult that worshipped the Symbiote God Knull, and awaited his return to Earth, Kasidy merged with the Grendell symbiote and created a brand-new Carnage symbiote out of it. He then infected maggots with the symbiote and began spreading them like diseases upon the population of homeless in San Francisco. These maggots burrowed into the brains of the people they came in contact with and turned them into mindless zombies, all of whom were controlled by Carnage.
5 Murdered Everyone Who Previously Wore A Symbiote
Realizing the power of the Symbiote God Knull, Kasidy realized he could become a God and spread carnage all over the planet. To do so, he needed to join with the various symbiote "codices" around the planet; the remnant symbiote DNA left behind inside anyone who had previously merged with a symbiote. However, to do so he needed to remove the codices from the spines of those previous symbiote hosts, so he started hunting down everyone and anyone who was ever hosted to a symbiote.
4 Murdered An Entire Bus-Load of Tourists
While searching for the codices of the members of Weapon V—a Weapons+ program that specialized in cloning the Grendell symbiote and creating individual symbiotes out of it—Carnage came across a tour bus heading in the direction of the Weapon V members. When Weapon-V recruited Weapon-H by abducting his mother-in-law, Weapon-H found the tour bus left behind, filled with headless bodies. Carnage acknowledged he didn't need to kill the people on-board, he just did it because he was bored.
3 Turned Everyone In Ravencroft Into Carnage Doppelgangers
During the Absolute Carnage, Spider-Man and Venom arrived at the Ravencroft Institute to escape with a Norman Osborn who believed himself to be Cletus Kasady. There, they realize that Carnage had already infiltrated the institute and taken over the guard, John Jameson, who had been infected by Carnage's Brain Worms early on.
Carnage then proceeds to infect everyone else with his Brain Worms, and turns them into Carnage Doppelgangers, much like he had done in the town of Dover, CO.
2 Killed Patricia Robertson
As part of his hunts for the codices of everyone who had previously been host to a symbiote, Carnage began to merge with other symbiotes, joining them into his own Carnage/Grendell symbiote, in an attempt to become even more powerful and closer to the Knull. One of the symbiotes he enlisted was Scream, who at the time was bonded to the young girl, Andi Benton. When Patricia Robertson—a former Venom-host—discovered Carnage's plan, she bonded with the Scream symbiote and used it to save Andi Benton but was killed by Carnage in the process. As a result, the Scream symbiote snapped out of Caarnage's influence and helped Benton escape, bonding with her in the process.
1 Re-Awakened The Symbiote God, Knull
After going after the codices of former symbiote hosts during the Absolute Carnage story-arc, almost all of whom were now dead, Kasidy became a dark, twisted version of Carnage known as Dark Carnage. He then fought Eddie Brock and Spider-Man for their codices and Brocks symbiote, which had already merged with several codices using a machine created by The Maker. After successfully merging with the Venom symbiote, Brock fought Carnage to the death. In the process, Carnage revealed that whether he lived or died, he had successfully set-up the stage for Knull's reawakening and his imminent arrival to Earth.