Claim: Venom is a fictional character.

Venom , or the Venom Symbiote , is a fictional character appearing in American comic books published by Marvel Comics , commonly in association with Spider-Man . Venom made his first appearance in The Amazing Spider-Man # 300 -LRB- May 1988 -RRB- . Venom was originally conceived as a supervillain , but has since become more of an antihero . Venom is a Symbiote , a sentient alien , with a gooey , almost liquid-like form . As with real-world symbiotes , it requires a host , usually human , to bond with for its survival . After bonding , the Symbiote endows its enhanced powers upon the host . When the Venom Symbiote bonds with a human , that new dual-life form refers to itself as `` Venom '' .   The Venom Symbiote 's first known host was Spider-Man , who eventually separated himself from the creature when he discovered its true 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 . According to S.H.I.E.L.D. , it is considered one of the greatest threats to humanity , alongside Magneto , Doctor Doom , and Red Skull .   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 Magazines 50 Greatest Comic Book Characters .