Óscar Gutiérrez (born December 11, 1974), better known by his ring name Rey Mysterio, is an American professional wrestler. He is currently signed to WWE, where he performs on the SmackDown brand. Widely regarded as one of the greatest professional wrestlers of all time, Mysterio is credited for popularizing cruiserweight wrestling, and is one of the world's most recognizable lucha libre wrestlers. The nephew of Rey Misterio Sr., Mysterio began his professional wrestling career in 1989, at age 14, on the independent circuit, before signing with Asistencia Asesoría y Administración (AAA) in 1992. After a brief period performing for Extreme Championship Wrestling (ECW), Mysterio departed to World Championship Wrestling (WCW) in 1996. In WCW, Mysterio helped popularize lucha libre in the United States, which led to the rise of cruiserweight wrestling divisions, while he also won the WCW Cruiserweight Championship five times and the WCW World Tag Team Championship three times. He then wrestled for Consejo Mundial de Lucha Libre (CMLL), and joined World Wrestling Entertainment (WWE) in 2002. In WWE, Mysterio won the Cruiserweight Championship three times, the World Heavyweight Championship, the Intercontinental Championship, and the United States Championship, all of them which he won twice, the WWE Championship once, and the Tag Team Championship four times. Mysterio departed WWE in 2015, and appeared in New Japan Pro-Wrestling (NJPW) and AAA, before returning to WWE in 2018, winning the U.S. Championship twice and SmackDown Tag Team Championship once with his son Dominik. All totaled, Mysterio has held 23 championships between WWE and WCW (including three world championships). In addition, he is WWE's 21st Triple Crown and Grand Slam champion, is a Royal Rumble match winner, and has headlined several WWE pay-per-view events. Early life Óscar Gutiérrez was born on December 11, 1974 in Chula Vista, California. Professional wrestling career Early career (1989–1992) Gutiérrez made his debut in Mexico on April 30, 1989, when he was 14 years old. He was trained by his uncle Rey Misterio Sr. and wrestled early on in Mexico where he learned the Lucha Libre high flying style that has been his trademark. He had ring names such as "La Lagartija Verde (The Green Lizard)" and "Colibrí (Humming bird)" before his uncle gave him the name of Rey Misterio Jr. In 1991, Mysterio was awarded "Most Improved Wrestler" in Mexico while wrestling as Colibrí. Asistencia Asesoría y Administración (1992–1995) In Asistencia Asesoría y Administración (AAA),