In 1992, Samu and Fatu signed with the company, managed by Samu’s father Afa. The team changed their name to the Headshrinkers, but their gimmick of Samoan wildmen remained the same. Rodney Anoa'i also signed with the WWF but he was repackaged as "Yokozuna" and the family ties between him and the Samoans were not mentioned on air. The team first made their presence known when they helped Money Inc. beat the Natural Disasters to win the World Tag Team Championship. 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 parts of 1994, the Headshrinkers maintained a position in the middle of the tag team division. They occasionally challenged for the titles and made sporadic PPV appearances feuding with teams like The Smoking Gunns and Men on a Mission. The Headshrinkers assisted their relative Yokozuna in a casket match against The Undertaker at the Royal Rumble. In April, 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. At King of the Ring on June 19, the Headshrinkers successfully defended their tag team titles against Yokozuna and Crush. Their run with the titles came to an 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 Sionne, who formed the "New Headshrinkers" with Fatu.
The storyline reason given for Samu’s departure was that he was not coping well with manager Lou Albano’s attempts to civilize the Headshrinkers, especially wearing boots. For the first time ever, one half of the Samoan Swat Team/Headshrinkers was not a member of the Anoa'i family nor a Samoan, as Sionne was from the island of Tonga. The New Headshrinkers made only one PPV appearance as a team which was at the Survivor Series where they were quickly eliminated. They were also both participants in the Royal Rumble. The only other notable appearance of the New Headshrinkers was as part of the tournament to crown new WWF tag team champions in late 1994/early 1995. The New Headshrinkers lost to Bam Bam Bigelow and Tatanka in the Semi-Finals. By July, the New Headshrinkers ended as Sionne signed with WCW. By the time Sionne left the WWF, the team was used to put over new teams such as Jacob & Eli Blu.
Fatu became a singles wrestler in 1995; the WWF repackaged Fatu by dropping the “savage" gimmick and revealing that Fatu could speak English and was raised in the US. Fatu became a "man of the streets" who spoke about growing up in the hood and being shot during a real-life drive-by. He started gaining weight from 280-300 lbs. During this time he was referred to as “Make a Difference" Fatu. After a short while, two men started to show up whenever Fatu was in the ring: Samu and his brother Lloyd Anoa'i, also known as "The Samoan Gangster Party". The Samoan Gangster Party, however, never got in the ring or confronted Fatu before he was repackaged and the whole angle was dropped.
The WWF then decided to give Fatu a total change, as he became a stereotypical “Middle Eastern" known as The Sultan, complete with a face mask to hide who was playing the gimmick. In storyline The Sultan's tongue was removed thus he never spoke in promos. He was managed by the Iron Sheik and Bob Backlund. He now weighted at 340 lbs. He was given a shot at Rocky Maivia’s Intercontinental Title at WrestleMania 13 but failed to win the gold. Fatu left the spotlight when the Sultan gimmick was dropped in early 1998 to get better training at Dory Funk Jr's.
After Fatu received gradual training, he returned on the November 13, 1999 episode of WWF Metal as Rikishi Fatu beating Julio Fantastico, the Rikishi name being a sumo wrestling term similar to his cousin Yokozuna's professional wrestling name. Then the name would become Rikishi Phatu, but was eventually shortened to Rikishi when he started teaming with Too Cool. He had gained a great deal of weight at 425 lbs, bleached his hair blonde, and exchanged his long trousers for a thong. Rikishi had a brief feud with Viscera before aligning with Too Cool, which consisted of Grand Master Sexay and Scotty 2 Hotty. It was at this point that Rikishi's popularity began to soar as their post-match dance routine became popular with fans. During the 2000 Royal Rumble, Rikishi eliminated seven opponents in the Royal Rumble match; he was eliminated by six wrestlers working together. Two of those seven were Too Cool themselves, whom Rikishi eliminated after they performed their dance routine in the middle of the match.
Rikishi became famous for giving wrestlers the Stink Face, as his butt was rubbed in the face of an opposing wrestler. This move became very popular with the fans. In May 2000, Rikishi and Too Cool feuded with Edge, Christian, and Kurt Angle, culminating in a victory at Judgment Day. After winning the Intercontinental Championship on the June 22 episode of SmackDown! from Chris Benoit, Rikishi qualified for the 2000 King of the Ring tournament. On June 25 he defeated Benoit and Val Venis in the quarter and semi-finals respectively, but both his opponents hit him with a steel chair after losing, weakening his shoulder and helping Kurt Angle defeat him in the finals. Stemming from Venis's attack at King of the Ring, Rikishi faced Venis on July 6 and lost his title after Tazz hit him with a television camera. Rikishi faced Venis in a Steel Cage rematch at Fully Loaded. In the course of the match, Rikishi ascended the cage and, in a move reminiscent of Jimmy "Superfly" Snuka, leapt from the top, splashing Venis. Rikishi was defeated by Venis shortly after when Tazz once again hit him with a television camera.
On October 9, Commissioner Mick Foley used a slip of the tongue from Scotty 2 Hotty to implicate Rikishi as the person who had run over Stone Cold Steve Austin at Survivor Series, as Scotty stated that he had been hanging out that night with Grand Master Sexay and Rikishi. However, Foley stated later that night in the ring that Rikishi at that point had not debuted yet. In actuality, this is not true, as Rikishi had debuted on the Saturday night before the '99 Survivor Series on WWF Jakked. Rikishi admitted injuring Austin, claiming that he had done so in order to allow his cousin The Rock to achieve stardom, insisting that Buddy Rogers, Bruno Sammartino, Bob Backlund, Hulk Hogan, and Austin - "The Great White Hope" - had always been pushed over Samoan performers such as High Chief Peter Maivia and Jimmy "Superfly" Snuka, who he believed had been held back, this turned Rikishi heel in the coming weeks. Austin immediately set out to obtain revenge, facing Rikishi in a No Holds Barred match at No Mercy. The match went to a no contest when Austin dragged Rikishi to the parking lot and attempted to run him over, but a police car drove in front of Austin's car, saving Rikishi. Though Austin was arrested, he had badly injured Rikishi, inflicting numerous cuts and bruises to his face. Later that night, Rikishi attempted to help The Rock retain the WWF Championship in a match against Kurt Angle, but "accidentally" kicked and crushed The Rock, allowing Angle to Angle Slam both men and win the title. After a number of instances where Austin was attacked backstage by an unseen assailant, it became clear that Rikishi had an accomplice. During a handicap match pitting Rikishi and Kurt Angle against Austin, Triple H came to the ring, seemingly to aid Austin, but swerved the audience by attacking Austin with a sledgehammer. This led to Triple H revealing that he had masterminded the assault, relegating Rikishi to his hired muscle. Rikishi never reclaimed the popularity he enjoyed throughout his initial run as Rikishi.
Rikishi lost to The Rock at Survivor Series. He then participated in the six-man Hell in a Cell match at Armageddon for the WWF Championship, during which Vince McMahon drove a flatbed truck to ringside in an effort to dismantle the cage and stop the match. However, Rikishi was chokeslammed from the top of the cell into the truck bed by the Undertaker. He won a match entitling him to enter the 2001 Royal Rumble at number 30. He even eliminated the Undertaker but he did not last long in the Rumble match before being eliminated by The Rock. After the return of Haku at the same event, Rikishi and Haku formed a tag team, and feuded with Kane and The Undertaker and The Hardy Boys. The team split when Rikishi was sidelined with an eardrum injury in May, and Haku was later released. Rikishi returned from injury on May 7, 2001 and was urged by Mick Foley to become a face again before delivering the Stink Face to Stephanie McMahon. He wrestled for several weeks before suffering a shoulder injury in May 2001 which caused him to miss much of the year.
Rikishi returned on December 6, 2001, delivering a Stink Face to Vince McMahon and solidifying his face status. Upon the WWE Brand Extension, Rikishi was drafted to SmackDown!. At Judgment Day, he faced Billy and Chuck in a "secret partner" match. His partner turned out to be Rico, Billy and Chuck's stylist. Despite Rico's best efforts to unfairly help Billy and Chuck, Rikishi and he won the match and became the Tag Team Champions. Rico would later cost his partner to lose the titles in a rematch.
Rikishi was not featured much in late 2002 and early-2003. He feuded with John Cena, Bill DeMott, and the Full Blooded Italians on SmackDown!. The return of "Rowdy" Roddy Piper led Rikishi to challenge him as Piper had hit Jimmy Snuka with a coconut years ago on Piper's Pit. At Backlash 2003, Piper's protege Sean O'Haire defeated Rikishi after Piper got hit with a coconut by Rikishi giving O'Haire time to hit the Widowmaker on Rikishi. Rikishi eventually formed a tag team with Scotty 2 Hotty, and the duo defeated the Basham Brothers for the WWE Tag Team Championship on February 5, 2004, holding them for two and a half months before losing them to Charlie Haas and Rico. Fatu, however, was released by WWE on July 16, 2004, following repeated requests from WWE to lose weight.
Rikishi made an appearance at the 2012 WWE Hall of Fame ceremony.