VENOM

Venom's opposite number was not engineered in a lab — he was a side effect of a good deed. In Amazing Spider-Man #568–569 (2008), Dan Slott and John Romita Jr.'s “New Ways to Die,” a separated and cancer-ridden Eddie Brock is volunteering at the F.E.A.S.T. shelter when its founder, philanthropist Martin Li, lays a healing hand on him. Li is secretly the crime lord Mr. Negative, and his power cures Eddie's cancer outright — while quietly rewriting the traces of symbiote still clinging to Eddie's white blood cells.

The rewrite only wakes up when the old life comes calling. Mac Gargan, then wearing the Venom symbiote with the Thunderbolts, storms F.E.A.S.T. hunting Spider-Man, finds Eddie instead, and the symbiote lunges for its favourite host — and recoils, transformed on contact into something new: a gleaming white symbiote with a black spider, which Eddie names Anti-Venom. Where Venom is a poison, this one is the antidote made flesh, able to burn other symbiotes on contact and to purge sickness and foreign substances from human bodies.

Eddie spent the suit the way he had earned it — on other people. He worked as a healer and symbiote-hunter until the Spider-Island crisis, when curing a Manhattan-wide spider-plague required the Anti-Venom symbiote itself as the raw material for the cure. Eddie gave it up without a fight, trading his second super-powered life for a city full of strangers — the full distance from the man who once sold this same alien for cash.