In 1983, Samu began appearing in the World Wrestling Federation (WWF) when Sika (part of the reigning WWF Tag Team Champions) was injured on March 12, 1983. Known simply as Samula, he helped The Wild Samoans defend the Tag Team Championship a handful of times while Sika recovered. After Sika returned, Samula remained in the WWF, backing up his father Afa and uncle. In January 1984, he received a shot at Bob Backlund, but ended up losing by disqualification. During the summer of 1984, Samula turned face after the Wild Samoans left the WWF. Samula twice teamed with Hulk Hogan during WWF's tours in Japan, both times facing Japanese legends Antonio Inoki and Tatsumi Fujinami. These matches were among the last matches Samula wrestled in the WWF before leaving in January 1985.
Samu debuted for World Class Championship Wrestling (WCCW) in the late 1980's alongside Fatu. The storyline was that Buddy Roberts brought the team, known as the Samoan SWAT Team, in to fight his fights against the Von Erich Family and former Fabulous Freebirds partner Michael Hayes. The SST was given a big push right away; presented as an unstoppable force the team was even allowed to beat hometown heroes Kerry and Kevin Von Erich for the WCCW Tag Team Titles on August 12, 1988. The Samoans remained undefeated in WCCW until they came up against Roberts’ former partner Michael Hayes and Hayes’ new partner, Steve Cox on September 12. The duo was not without the gold for long as they recaptured the title only four days later. Hayes and Cox beat the Samoan SWAT Team for the title once again on October 15, 1988, but this time they only held the gold for two days before they lost it back to the SST.
The Samoan SWAT Team made their pay-per-view debut at AWA SuperClash III, the first (and only) pay-per-view that the American Wrestling Association ever presented. The Samoans successfully defended their WCCW Tag Team Titles against Michael Hayes and Steve Cox. In the beginning of 1989, the Samoans left WCCW, forcing the tag titles to be vacated due to the sudden departure.
The Samoan SWAT Team signed with World Championship Wrestling and was brought in as manager Paul E. Dangerously's replacements for the "Original" Midnight Express, who had left the promotion. The Samoans also took over the "Original" Midnight Express’ feud with the Midnight Express, beating the team at Clash of the Champions VI on April 2, 1989. At the 1989 Great American Bash, the Samoans teamed with former rival Michael Hayes, Terry Gordy and Jimmy Garvin, losing a WarGames match to The Road Warriors, the Midnight Express and Steve Williams. In the fall of 1989, Paul E. Dangerously was phased out and the Samoans were given a new manager: "The Big Kahuna" Oliver Humperdink. Their ranks were also bolstered by the addition of The Samoan Savage. The Samoans started to lose more and more matches as 1989 drew to a close, but their fortunes appeared to be changing due to the injury to Sid Vicious. Because Vicious was injured, The Skyscrapers had to pull out of the "Iron Team Tournament" at Starrcade 1989 and the Samoan SWAT Team were chosen to be their replacements – Fatu and the Samoan Savage with no explanation of why the more experienced Samu was not chosen. For the remainder of the Samoan SWAT Team's time in WCW, Fatu and the Samoan Savage competed under the name while Samu made a few singles appearances.
In 1992, Samu and Fatu signed up with the World Wrestling Federation, managed by Samu's father Afa. The team changed their name to the Headshrinkers, but their gimmick remained the same: Samoan wildmen. The team first made their presence known when they helped Money Incorporated beat the Natural Disasters to win the WWF World Tag Team Titles. Early in their run with the WWF, the Headshrinkers feuded with the Natural Disasters and the recently formed High Energy. Between 1992 and the early part of 1994, the Headshrinkers maintained a position in the middle of the tag team division, occasionally challenging for the titles and making sporadic pay-per-view appearances, feuding with teams like The Smokin' Gunns and Men on a Mission. The Headshrinkers assisted their relative Yokozuna in a casket match against The Undertaker at the 1994 Royal Rumble. In April 1994, the Headshrinkers turned face and challenged then-Tag Team Champions The Quebecers; with the addition of manager Lou Albano the team won the gold on April 26, 1994. At King of the Ring 1994 on June 19, the Headshrinkers successfully defended their Tag Team Titles against Yokozuna and Crush. Their run with the titles came to a surprising end on an untelevised card on August 28, where they lost the titles to Shawn Michaels and Diesel. The title change happened just one day before they were scheduled to defend against Irwin R. Schyster and Bam Bam Bigelow. Soon after the title change, Samu left the WWF to recover from injuries and was replaced by Sione.
After being away from the spotlight for a while, Samu returned to the WWF in 1995. Samu, along with his cousin Rosey, were known as "The Samoan Gangster Party" with Samu being known as "Sammy the Silk" and Rosey being "Big Matty Smalls". The two men did not wrestle for the WWF, but watched Fatu from afar as the former Headshrinker tried to turn himself into a positive role model for kids on the street. The angle never went anywhere, as the Samoan Gangster Party never got in the ring or confronted Fatu before he was repackaged and the whole angle was dropped. The tag team did wrestle a few house shows in May 1996.
In 1996, The Samoan Gangster Party worked for Extreme Championship Wrestling, feuding mainly with The Gangstas in a short but intense war between the two "Gangsta" factions.
On March 31, 2007, Samu and Rosey inducted The Wild Samoans, Afa and Sika, into the WWE Hall of Fame.