Gladiator is a fictional character appearing in American comic books published by Marvel Comics. He first appeared in X-Men #107 and was created by writer Chris Claremont and artist Dave Cockrum. Gladiator, whose given name is Kallark, is a Strontian, and like others of his race has the capacity for great strength and various superpowers, but can only use them when he is completely devoted to a purpose; his abilities increase and decrease in accordance with his level of confidence. He was born on Strontia, which is part of the Shi'ar Empire and he is the leader of their Imperial Guard. He was also a member of the Annihilators, Dark Guardians, and Guardians of the Galaxy.