Juggernaut (Cain Marko) is a fictional character appearing in American comic books published by Marvel Comics. The character, who first appeared in X-Men #12 (July 1965), was created by writer Stan Lee and artist/co-writer Jack Kirby. Cain Marko is the son of Kurt Marko, who becomes Charles Xavier's stepfather when he marries Sharon Xavier after the death of her husband Brian, making Cain Charles' step-brother.

Since his debut, the Juggernaut has appeared in over five decades of Marvel publications, featuring prominently in the X-Men titles and starring in two one-shot solo publications.

More Info: en.wikipedia.org