Miguel Ángel López Días (January 8, 1958 – December 20, 2024), known professionally as Rey Misterio Sr., was a legendary Mexican luchador and trainer who pioneered the wrestling style later popularized by his famous nephew, Rey Mysterio. He made his professional debut on January 6, 1976, and gained international recognition when he represented Mexico alongside Konnan at World Championship Wrestling's Starrcade 1990 event. In 1987, he co-founded a wrestling gym with Negro Casas and Super Astro, where he trained a remarkable roster of future stars including Rey Mysterio, Konnan, Psicosis, and Cassandro. Beyond the ring, he appeared in the horror film El Mascarado Massacre and came from a deeply wrestling-centered family, with his son wrestling as El Hijo de Rey Misterio and his grand-nephew being Dominik Mysterio. Over his career, he captured numerous championships across promotions like WWA and IWC, and was inducted into the Tijuana Sports Hall of Fame in 2006. He passed away on December 20, 2024, at the age of 66, leaving behind a lasting legacy as one of Mexico's most influential wrestling figures.