In 1989, Calaway joined World Championship Wrestling (WCW) as a villain and adopted the ring name "Mean Mark" Callous, a name devised for him by Terry Funk. He was portrayed as a morbid character; he wore predominantly black ring attire and was described by announcer Jim Ross as having a fondness for pet snakes and the music of Ozzy Osbourne. Callous was promptly drafted into The Skyscrapers tag team to replace a legitimately injured Sid Vicious and he made his debut on January 3, 1990, in a match later televised against Agent Steel and Randy Harris. The new team gained some notoriety at "Clash of the Champions X" when they beat down The Road Warriors after their match. However, Callous' partner Dan Spivey left WCW days before their Chicago Street Fight against The Road Warriors at WrestleWar. Callous and a replacement masked Skyscraper were defeated in the street fight and the team broke up soon afterwards. Now a singles wrestler, Callous took on the guidance of Paul E. Dangerously (Paul Heyman) and defeated Johnny Ace at Capital Combat and Brian Pillman at "".