Born in the South Pacific island which shares his first name, Tonga Uliuli Fifita was entrenched in athletic competition from an early age. He attended Tonga College, an all-boys school, where the top sport was rugby. After a troupe of Japanese sumo wrestlers visited the island kingdom in an attempt to drum up local interest in the sport, Fifita was selected at age 14 to join a contingent of Tongan wrestlers for further sumo training in Japan. (Fellow Tongan sumo wrestler Sione Vailahi aka 'The Barbarian' would later follow the same career path.) However, with the generous amounts of money Fifita saw professional wrestlers making in Japan, he decided to change careers, turning pro at 18. After touring various circuits throughout Japan and Canada, he debuted in the World Wrestling Federation in 1985 as 'King Tonga'. He immediately made an impact as a fan favorite when he bodyslammed Big John Studd on an episode of WWF Superstars of Wrestling (1986).

He remained with the company for the next six years, turning heel as 'Haku' after aligning himself with manager Bobby Heenan. In 1987, he formed 'The Islanders' tag team with the 'Tonga Kid' Sam Fatu. He was crowned 'King' of the WWF in 1988, and teamed with Andre the Giant to defeat Demolition for the WWF tag team championships in 1989. He later turned up in World Championship Wrestling, appearing on WCW Monday Nitro (1995) & WCW Thunder (1998) with an even meaner streak as 'Meng' - master of the Tongan death grip. By 2000, however, with mis-management and financial chaos running rampant in WCW, Tonga was let out of his contract, and hired back on a per-event basis. While celebrating a reign as WCW Hardcore champion, Tonga was contacted by the rival WWF within mere days of his title win at WCW Sin (2001), and was offered a contract. He returned to the WWF soon after, as the 29th entrant in the Royal Rumble (2001). That turned out to be a good business move for him, as WCW was soon shut down and sold off to the WWF. This time around he formed a temporary alliance with fellow Islander (& Tonga Kid's brother) Rikishi, feuding with the Undertaker & Kane on _"Raw Is War" (1997)_ & WWE SmackDown (1999).

Though now mainly retired from in-ring competition, he continues to be involved in other commercial ventures such as Tri Women's Fitness, where WWE Superstars Torrie Wilson & Victoria are known to have got their start prior to their wrestling careers. He also now works as Detail Manager for Central Florida's David Maus Toyota. Tonga now lives in Poinciana, Florida with his wife Dorothy, sons Tevita, Alipate & Taula and daughter Vika.