Cigarette Smoking Man (abbreviated CSM or C-Man; sometimes referred to as Cancer Man or the Smoking Man) is a fictional character and the primary antagonist of the Fox science fiction-supernatural television series The X-Files, at least from the second to seventh series, and again in the tenth. He serves as the arch-nemesis of FBI Special Agent Fox Mulder. In the show's sixth season, his name is said to be C.G.B. Spender, but Dana Scully suggests this is one of "hundreds of aliases"; the show's characters and fans continue to refer to him by variations of "the Smoking Man" because he is almost always seen chain-smoking Morley cigarettes.