Mendez II was a mutant and one of the earliest progenitors of the Mendez Dynasty. Very little is known about this mutant, except for the fact that he was held in high regard, and was instrumental in the formation of the Doomsday cult that would evolve. A psalm attributed to Mendez II is included in the mutants' Doomsday prayer book, and a bust of him was constructed and placed upon a plinth within an air tunnel passageway outside of the mutant cathedral.