James "Jamie" Madrox is a supporting character in the X-Men franchise. He is Multiple Man, a changeling (species that predates the mutants) with the ability to make copies of himself. He became an ally of the X-Men after Professor X cured Jamie of his madness. Despite turning down some offers to join the X-Men, James eventually joined the team and later became a member of X-Corps, X-Factor, and X-Factor Investigations.
He was created by Len Wein, Chris Claremont and John Buscema, and first appeared in Giant Size Fantastic Four #4 (February 1974).