Cosplay attendee in his costume, as Venom from Spider Man.
Venom was originally conceived as a super villain, but has since become more of an antihero. Venom is a Symbiote, a sentient alien, with a gooey, almost liquid-like form. 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".
Cosplay, a contraction of the words costume play, is a performance art in which participants called cosplayers wear costumes and fashion accessories to represent a specific character.