Anti-Venom is a fictional antihero appearing in Comic books published by Marvel Comics. It first appeared in The Amazing Spider-Man #569 (August 2008), and was created by Dan Slott and John Romita Jr. The creature belongs to a race of amorphous extraterrestrial parasites known as the Symbiotes and is regarded as Venom's symbiotic brother. His physical features include white "skin", a black face, and spider symbol across his chest.
The 2008 story New Ways to Die features the first appearance of Anti-Venom. Eddie Brock gets a job at a soup kitchen under Martin Li, who unknowingly cures Brock's cancer using his Lightforce abilities. After Brock is attacked by Mac Gargan (the Venom symbiote's current host), the Venom symbiote attempts to reunite with Brock, reacting with the remnants of the Lightforce and creating the Anti-Venom symbiote. During the Spider-Island event, Brock sacrifices the Anti-Venom symbiote to cure the Spider-Queen's spider-virus.
In the "Venom Inc." storyline, Venom is captured by the Life Foundation and was experimented on. The Life Foundation accidentally pour hydrochloric acid on Venom, giving him a white appearance and new abilities, including intangibility. Venom escapes the Life Foundation and bonds with Flash Thompson, who uses it to become "Agent Anti-Venom".
Anyone possessed by the Anti-Venom symbiote possesses superhuman strength, durability, and stamina, an accelerated and fast healing factor, genetic memory, detection of its Symbiote offspring, wall-crawling, web-generating abilities, spider-senses, immunity to Spider-Man's spider-senses, and camouflage.
The original Anti-Venom symbiote is immune to heat and sound-based attacks, the traditional weaknesses of symbiotes. In addition, the Anti-Venom symbiote can produce antibodies that can "cure" a person afflicted by things like radioactivity, parasites, diseases, and drugs. The new Anti-Venom symbiote used by Flash Thompson has the ability to heal physical injuries as well.
In What If? Peter Parker became Kraven the Hunter where Peter Parker killed Kraven the Hunter and replaced Kraven as the new hunter, Madame Web hired Anti-Venom, Spider-Woman and Mac Gargan to stop Peter. Despite being successful in mortally injuring him, they were all defeated.