José de Jesús Díaz Mendoza, known by the ring name of Villano I, was a Mexican luchador enmascarado, or masked professional wrestler. He was the son of luchador Ray Mendoza, and the first of the five Díaz Mendoza brothers to become a professional wrestler, although not the oldest. His older brother Alfredo wrestled as Villano II until his death in 1989, while his younger brothers wrestle under the names Villano III (Arturo), Villano V (Raymundo), and Villano IV (Tomás).

Lucha libre is the term for the style of professional wrestling originating in Mexico. Since its introduction to Mexico in the early 20th century, it has developed into a unique form of the genre, characterized by colorful masks, rapid sequences of holds and maneuvers, and "high-flying" maneuvers, some of which have been adopted in the United States, Japan, and elsewhere. The wearing of masks has developed special significance, and matches are sometimes contested in which the loser must permanently remove his mask, which is a wager with a high degree of weight attached. Tag team wrestling is especially prevalent in lucha libre, particularly matches with three-member teams, called trios.