Shortened name of James Arthur Madrox also known as The Multiple Man.

From the X-Men series, more specifically a member of the X-Factor team. He possesses the mutant ability to create identical physical duplicates of himself when violently struck (or when he strikes himself). It is not yet known precisely how Madrox's power works: although the duplicate bodies seem to "split off" from within him, he does not undergo a mitosis process like that of cells, creating identical entities each with half the mass of the original. Each duplicate possesses the same mass as the original. He does not appear to be transmuting nearby elements into his likeness either. If he is indeed converting energy to matter, the expected devastating release of energy must be shunted elsewhere since it is not in evidence.