Venom is a fictional character appearing in American comic books published by Marvel Comics, commonly in association with Spider-Man. The character is a sentient alien Symbiote with an amorphous, liquid-like form, who requires a host, usually human, to bond with for its survival. After bonding with a human host, the Symbiote bestows its enhanced powers upon the host. When the Venom Symbiote bonds with a human, that new dual-life form usually refers to itself as "Venom". The Symbiote was originally introduced as a living alien costume in The Amazing Spider-Man #252 (May 1984), with a full first appearance as Venom in The Amazing Spider-Man #300 (May 1988).
The Venom Symbiote's first human host was Spider-Man, who eventually separated himself from the creature in The Amazing Spider-Man #258 (November 1984) (with a brief rejoining in Web of Spider-Man #1, five months later), when he discovered its true nefarious nature. The Symbiote went on to merge with other hosts, most notably Eddie Brock, its second and most infamous host, with whom it first became Venom and one of Spider-Man's archenemies.
Comics journalist and historian Mike Conroy writes of the character: "What started out as a replacement costume for Spider-Man turned into one of the Marvel web-slinger's greatest nightmares." Venom was ranked as the 22nd Greatest Comic Book Villain of All Time in IGN's list of the top 100 comic villains. IGN also ranked Mac Gargan's incarnation of Venom as #17 in their list of "The Top 50 Avengers", while the Flash Thompson incarnation was ranked as #27. The character was listed as #33 on Empire's 50 Greatest Comic Book Characters.