Giacomo Costa was an Italian Australian professional wrestler best known by his ring name, Al Costello. Costello was the first professional wrestler to be nicknamed "The Man of a Thousand Holds" because of his innovative and very technical style.

Costello was the creator and original member of the tag team The Fabulous Kangaroos, whose "Ultra Australian" gimmick complete with boomerangs, bush hats and the song "Waltzing Matilda" as their entrance music, existed in various forms from 1957 until 1983. Costello was either an active wrestler, or a manager in all versions of The Fabulous Kangaroos. He and Roy Heffernan are arguably the most famous version of The Kangaroos, regarded as one of the top tag teams to ever compete in professional wrestling, and are often credited with popularizing tag team wrestling in the late 1950s and 1960s.

Costello later formed other versions of The Fabulous Kangaroos with Ray St. Clair, Don Kent and Tony Charles. He also managed the team of Don Kent & Bruno Bekkar and later on "Johnny Heffernan" under The Fabulous Kangaroos name.

After retiring from wrestling, Al Costello became the head of security at College Harbor, Florida. In 1992, at the age of 71, Costello retired from his job in Florida and began teaching wrestling. He also started to manage The New Fabulous Kangaroos in 1993, a team consisting of Mickey Doyle and Denny Kass who worked for "Motor City Wrestling" (MCW). By the fall of 1993, Mickey Doyle had been replaced by a young wrestler by the name of Al Snow; with Costello’s help The New Fabulous Kangaroos defeated "Canadian Lighting" (Otis Apollo and "Irish" Bobby Clancy), on December 29, 1993, to win the MCW Tag Team Championship. On May 14, 1994, Kass and Snow defeated Canadian Lighting again to win the Border City Wrestling (BCW) Can-Am Tag Team Championship, unifying the two tag team championships. A week later, The New Fabulous Kangaroos lost both sets of titles to Scott D'Amore and "Irish" Bobby Clancy. After losing the unified MCW/BCW Tag Team championships, The New Kangaroos split up; Snow focused on his World Wrestling Federation career while Costello retired for good, never making another wrestling related appearance.

On January 22, 2000, Costello died at age 80 from a combination of pneumonia and heart problems. In 2003, Al Costello and Roy Heffernan became the first tag team to ever be inducted into the Professional Wrestling Hall of Fame. Since that time, the Hall of Fame has honored other tag teams, but The Fabulous Kangaroos were given the honor of being the first. In the tradition of the Kangaroos, they were "billed as champions on arrival" one last time.