Early career (1987–1990)
Calaway began training under Buzz Sawyer in late 1986, whom Calaway disliked, who Calaway stated had lacked commitment and provided a limited education. Performing under a mask as Texas Red, Calaway wrestled his first match on June 26, 1987 for World Class Championship Wrestling (WCCW), losing to Bruiser Brody at the Dallas Sportatorium. He was accompanied to the ring by Percival “Percy” Pringle III, who would later serve as his manager in the WWF (as Paul Bearer). Two myths have circulated regarding Calaway’s beginnings in the industry, the first being that he made his in-ring debut in 1984, and the second being that he was trained by former WCCW colleague Don Jardine (aka The Spoiler). While never trained by Jardine, Calaway was an admirer of his work and would inherit his signature top rope walk.
In 1988, Calaway joined the Continental Wrestling Association (which became part of the United States Wrestling Association (USWA) after Jerry Jarrett bought WCCW and merged the two organizations into one), wrestling under several gimmicks. On February 2, 1989, managed by Dutch Mantel, he was reintroduced as The Master of Pain, a character fresh out of the United States Penitentiary, Atlanta after serving five years (much in solitary confinement) for killing two men in a fight. After his second match the next week, he stayed in the ring by challenging USWA Unified World Heavyweight Champion Jerry Lawler to an impromptu match. The Master of Pain easily dominated Lawler until Mantel entered the ring and called him off. Lawler agreed to a title match and on April 1, The Master of Pain won his first professional wrestling championship. He held it for just over three weeks before Lawler became the first man to pin him, winning it back. While performing as The Punisher, Calaway won the WCWA Texas Heavyweight Championship on October 5, 1989, when Eric Embry forfeited the title.
World Championship Wrestling (1989–1990)
In 1989, Calaway joined the 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 Clash of the Champions XI: Coastal Crush.
Calaway began to question his future in WCW after being told by booker Ole Anderson, during contract renewal talks, that nobody would ever pay money to watch him perform. Callous wrestled Lex Luger for the NWA United States Heavyweight Championship at The Great American Bash, but was pinned. According to WWF / E executive Bruce Prichard, “feelers” had already been sent out to the WWF by Heyman: Calaway wrestled the match with a dislocated hip knowing that he was being watched by Vince McMahon. McMahon initially did not express interest, but Prichard encouraged him to speak with Calaway when WCW traveled to New Jersey for a house show in the Meadowlands on August 24. The meeting between the two went well and Calaway gave notice to WCW on August 27. His final match was on September 7 at a WorldWide taping in Amarillo, Texas in which he defeated Dave Johnson.
During his time in WCW, Calaway briefly wrestled in New Japan Pro Wrestling (NJPW) as “Punisher” Dice Morgan. After leaving WCW, he briefly returned to the USWA to participate in a tournament to determine the new USWA Unified World Heavyweight Champion; He defeated Bill Dundee in the first round, but lost to Jerry Lawler in the quarterfinals.
Debut and early feuds (1990–1991)
In October 1990, Calaway signed with the World Wrestling Federation (WWF). He made his debut as Kane the Undertaker at a taping of Superstars on November 19, 1990. Calaway made his official on-camera debut on November 22 at Survivor Series as a villainous character when he was the mystery partner of Ted DiBiase’s Million Dollar Team. Approximately one minute into the match, The Undertaker eliminated Koko B. Ware with his finisher, the Tombstone Piledriver. He also eliminated Dusty Rhodes before being counted out; However, his team won the match with DiBiase being the sole survivor. During the match, Calaway was referred to as The Undertaker, omitting the name ‘Kane’, which was dropped shortly after the event (and seven years later was given to another wrestler who eventually became Undertaker’s younger brother of the same name). At the same time, The Undertaker switched managers from Brother Love to Paul Bearer – a histrionic, ghostly character, almost always seen bearing an urn, which he used to revive The Undertaker’s strength whenever Undertaker fell victim to his opponents. Undertaker placed his defeated opponents (almost always jobbers) in a body bag and carried them to the back. Throughout the end of 1990, The Undertaker mostly picked up squash victories against jobbers on Superstars of Wrestling and Wrestling Challenge tapings. He was a participant in the 1991 Royal Rumble match which was won by Hulk Hogan. He continued picking up victories in squash matches leading up to his first feud in the WWF with “Superfly” Jimmy Snuka.
WWF Champion (1991–1994)
He made his WrestleMania debut at WrestleMania VII on March 24, 1991, quickly defeating “Superfly” Jimmy Snuka.  He began his first major feud with The Ultimate Warrior when he attacked Warrior and locked him in an airtight casket on the set of Paul Bearer’s Funeral Parlor interview segment. He would later lose to Warrior in the first-ever body bag challenge in WWF history. At King of the Ring 1991, Undertaker defeated Animal in a qualifying match before fighting Sid Vicious to a double disqualification in the Semi-Final, which saw both men eliminated from the King of the Ring tournament. The Undertaker defeated Hulk Hogan to win his first WWF Championship at Survivor Series with the help of Ric Flair and thus became the youngest WWF Champion in history, until having this record broken by Yokozuna in April 1993 at WrestleMania IX. WWF President Jack Tunney ordered a rematch for this Tuesday in Texas six days later, where he lost the title back to Hogan.  However, due to the controversial endings of the two title matches between The Undertaker and Hogan, the title was vacated by Tunney. The title was awarded to Ric Flair as the winner of the 1992 Royal Rumble match.