Mephistomon X

Mephistomon X is a Digimon and carrier of the X-Antibody.

Etymologies
Standard naming scheme for Digimon who are not natural carriers of the X-Antibody. Base name shares official romanization with Mephistomon. English media shortens "X-Antibody" to "X".
 * Mephismon X (メフィスモン (Ｘ抗体))
 * X-Antibody.
 * X-Antibody.