Juan Valdez Valentino is a Mexican luchador or professional wrestler, currently performing under the ring name X-Fly. He is also known as the original El Mosco de la Merced ("Mosquito of the Mercy"), a name which has since been given another luchador.

He is best known for his stints with the AAA promotion, the latest while representing Los Perros del Mal. On June 6, 2010, X-Fly returned to AAA at the conclusion of Triplemanía XVIII, taking part in an angle, where the event was invaded by wrestlers from Perros del Mal Producciones, led by El Hijo del Perro Aguayo.Los Perros del Mal then came together with La Legión Extranjera to form La Sociedad.