Adnan first arrived in the World Wide Wrestling Federation in the 1970's under the Native American gimmick of Billy White Wolf and won the World Tag Team Titles with Chief Jay Strongbow. White Wolf was soon involved in an angle where he had his neck broken by Ken Patera via a swinging neckbreaker on television. After he left the company for his neck surgery, the 'Indians' were stripped of their titles.
In 1981, he debuted in the American Wrestling Association as Sheik Adnan El Kaissey, where his stated goal was to win the AWA Title from champion Nick Bockwinkel. He failed at that task, so he then enlisted Jerry Blackwell, now wearing a sheik's outfit and renamed Sheik Ayatollah Jerry Blackwell, to team with him to try to win the AWA Tag Team Titles. That failed too, so Adnan bought Ken Patera from manager Bobby Heenan to team with Blackwell, and Adnan would act as Blackwell and Patera's manager. The team of Blackwell and Patera captured the AWA World Tag Team Titles from Greg Gagne and Jim Brunzell. Adnan had to quit wrestling when he was injured, which is the real reason Patera was brought in to team with Blackwell. On April 23, 1983, at the AWA Super Sunday, he teamed with Blackwell in a tag team match against Verne Gagne and Mad Dog Vachon which they lost. In 1986, at AWA WrestleRock, he lost to Verne Gagne in a steel cage; he then teamed with Boris Zhukov in a tag team match against The Midnight Rockers (Marty Jannetty and Shawn Michaels). Kassie later left the AWA, but returned on a November 26, 1988 card in Bloomington, Minnesota, when he managed The Iron Sheik in a match against Sgt. Slaughter.
In the World Wrestling Federation, during the summer of 1990, he allied with Sgt. Slaughter as General Adnan, and managed him during his pro-Iraqi gimmick in a feud with Hulk Hogan and The Ultimate Warrior. During this feud, Slaughter won the WWF Title from the Warrior at the 1991 Royal Rumble, and lost it a couple of months later to Hogan at WrestleMania VII. The pair were then joined by Slaughter's former nemesis, The Iron Sheik to form the Triangle of Terror, and who was renamed Colonel Mustafa. Adnan also headlined SummerSlam 1991 with Slaughter and Mustafa against Hogan and Warrior. After Slaughter turned face, Adnan continued to manage Col. Mustafa until leaving the WWF shortly after Royal Rumble 1992.
Adnan passed away on September 6, 2023.