Mark William Calaway, born March 24, 1965, is a retired American professional wrestler who wrestled for the World Wrestling Federation (WWF), later known as World Wrestling Entertainment (WWE). He is best known by his ring name, The Undertaker. Calaway debuted in 1989 with World Championship Wrestling (WCW) and joined the WWF in 1990. He is a four-time WWE Champion and three-time World Heavyweight Champion.