In 1982, Bundy joined World Class Championship Wrestling. He debuted as Big Daddy Bundy. He wore blue jeans with a rope belt. After a dispute with the Von Erich family, Bundy was recruited by "Playboy" Gary Hart and dramatically reintroduced as King Kong Bundy, wearing the black singlet for the first time to signify his change. He lost his hair during the feud, adding to his signature look.
Bundy was Fritz Von Erich's opponent for Fritz's 1982 retirement match at the Fritz Von Erich Retirement Show held at the Texas Stadium.
Bundy officially debuted in the World Wrestling Federation (WWF) on the March 16, 1985 airing of WWF Championship Wrestling, defeating Mario Mancini. First managed by Jimmy Hart, he was immediately pushed with dominating victories over all of his opponents. Bundy also developed a gimmick of demanding a five-count from the referee while pinning an opponent, to show how badly he had beaten his hapless opponent. He defeated S.D. "Special Delivery" Jones in what was announced as only nine seconds at the first WrestleMania at Madison Square Garden (it was actually about 17 seconds).
In September 1985, Hart traded Bundy to manager Bobby Heenan in exchange for Adrian Adonis and The Missing Link. After joining the Heenan Family, Bundy feuded extensively with André the Giant, a feud which started during an angle where Bundy interfered in one of André's matches and delivered several splashes, giving the Giant a kayfabe broken sternum. They feuded for several months, including a pair of tag team matches on Saturday Night's Main Event II and III in late 1985, where Bundy, and André's other nemesis, Big John Studd, first faced André and Tony Atlas and then André and WWF World Heavyweight Champion Hulk Hogan. On September 23, 1985, Bundy faced André the Giant at Madison Square Garden in a match billed as "the Colossal Jostle". André dominated the match, with the match ending after Big John Studd came from the locker rooms to Bundy's aid and attacked the Giant, causing a disqualification.
Bundy also began targeting Hogan and the WWF World Championship in late 1985. At Saturday Night's Main Event V, Hogan was dominating challenger the Magnificent Muraco when Bundy (with Heenan in tow) ran to ambush Hogan. With Muraco's help, Bundy repeatedly gave Hogan avalanches and big splashes, which caused Hogan to severely bruise his ribs (kayfabe). Bundy demanded a match and claimed Hogan was afraid of him, setting up their feud. Hogan demanded revenge and agreed to a steel cage match for the WWF World Heavyweight Championship as the main event of WrestleMania 2 in the Los Angeles portion of the event, which Hogan won.
Later in 1986, Bundy reformed his tag team partnership with Studd and began a feud with The Machines (Super Machine and Big Machine) and often joined by Andre the Giant (as the Giant Machine). The storyline was that Bundy and Studd, along with Heenan, claimed that the Giant Machine was a masked Andre the Giant, and was competing under the mask and alias to circumvent an earlier suspension (due to no-showing for an event), but none of them ever proved that Andre and the Giant Machine were one and the same. Eventually, Bundy and Studd began teaming up with Heenan in a series of six-man tag team matches against the Machines (usually, Big and Super; as Andre's health was starting to deteriorate at this time, the Giant Machine made occasional appearances, but more often than not, it was either Captain Lou Albano or a number of popular faces—often, Hogan, Roddy Piper and others—who teamed with the other Machines). Bundy and Studd were regularly beaten, but won their last match over the Super and Big version of the Machines at Madison Square Garden. Also in the latter half of 1986, Bundy and Studd received shots at the WWF Tag Team Championship against The British Bulldogs, but were unsuccessful, often losing by disqualification. Studd left the WWF shortly after their last match with the Machines, and Bundy went back to singles competition.
At WrestleMania III, Bundy was involved in a mixed six-man tag team match, teaming up with midget wrestlers Little Tokyo and Lord Littlebrook against Hillbilly Jim, the Haiti Kid and Little Beaver. During the match, after being pestered by Beaver, Bundy body-slammed him and delivered a big elbow, causing his team's disqualification and his own tag partners to turn against him. At the 1987 King of the Ring on September 4, Bundy made it to the finals of the King of the Ring tournament, where he was defeated by Randy Savage. In November 1987, Bundy defeated Hulk Hogan via a count-out on an episode of Saturday Night's Main Event XIII, but lost to Hogan in a rematch on the next episode of the series; the match was best known for the referee becoming legitimately injured when he was accidentally caught between Hogan and a charging Bundy, and Andre the Giant's post-match attack of Hogan shortly after Bundy left ringside. Although no longer appearing on the WWF's syndicated television shows, Bundy continued to wrestle house shows in early 1988 (often losing to Bam Bam Bigelow); his last match during his initial WWF run was a televised match at Madison Square Garden in February 1988, teaming up with One Man Gang in a loss to Don Muraco and The Ultimate Warrior.
In 1993, he wrestled in the main event of Extreme Championship Wrestling's inaugural November to Remember supercard, appearing as the mystery tag team partner of Terry Funk in a losing effort against Road Warrior Hawk and Sabu.
Bundy returned to the WWF in the fall of 1994 as a member of Ted DiBiase's stable, The Million Dollar Corporation. He had a successful pay-per-view return at Survivor Series, when he and fellow "Million Dollar Team" member Bam Bam Bigelow survived a match against Lex Luger's "Guts and Glory" team. Bundy was then billed as a favorite in the 1995 Royal Rumble, but lasted only three minutes before being eliminated by another big man, Mabel. Bundy made his return to WrestleMania at WrestleMania XI, where he was defeated by the Undertaker, Bundy was later pushed down the card before being released in October 1995 after teaming with Kama and losing to Bam Bam Bigelow and Henry O. Godwinn for a dark match for WWF Superstars of Wrestling.
On March 4, 2019, Bundy passed away.