Vaccine Man emerged from the planet's accumulated pollution—basically nature's immune response made flesh. He saw himself as Earth's antibody, designed to eliminate humanity and cleanse the world of what he viewed as an infection. In his own words, he was meant to "vaccinate" the planet against mankind itself.
He's best known as Saitama's very first opponent in One Punch Man, which pretty much tells you how that fight went. Though he positions himself as some kind of righteous force, Vaccine Man is ultimately just a monster born from humanity's own negligence—a living consequence of environmental destruction.
Content compiled by AnimeList.moe from publicly available sources.
