He was not originally in the comics, no. But when Marvel did one of the best alternate story arcs ever, the Age of Apocalypse, he was in that. It was a four month run where Apocalypse took over the world, and he was part of the X Men. Of course, once the AOA was over, so was he. He has been resurrected in the Exiles series, I believe. But I don't read them, so I'm not too sure...