In 1998, Tori was hired by the World Wrestling Federation (WWF). She debuted on the December 28 episode of Raw, entering the ring before a match to hand Sable a yellow rose. She continued in becoming an obsessed fan over the next few weeks, constantly at ringside during Sable's matches. At the Royal Rumble, she helped Sable defeat Luna Vachon in a strap match. She later introduced herself as Tori and tried to gain the respect of Sable, who continually degraded and humiliated her. As a result, Tori challenged Sable to a match for the Women's Championship at WrestleMania XV, which Sable won following interference from her bodyguard, Nicole Bass.
Tori feuded with Jacqueline in April and May 1999, and then began pursuing Ivory's Women's Championship in July. After Ivory defeated Tori at SummerSlam, their feud became more and more heated, leading to the first ever WWF women's hardcore match on the September 6, 1999 edition of Raw. Ivory retained her title once more in a match which involved Tori having a mirror smashed over her head and being burnt with an iron. On September 26, Tori attempted to gain a measure of retribution by attacking Ivory during a match, but instead was pushed into a crate by Ivory.
Tori returned in November and soon became the on-screen girlfriend of Kane. On December 16, Tori complained to Triple H and Stephanie McMahon about Kane, by now feuding with his former tag team partner X-Pac, an ally of Triple H, being placed in a handicap match. Stephanie retorted by challenging Tori to a match that night, which she accepted. Stephanie, however, replaced herself with X-Pac, who defeated Tori with ease as Kane was ambushed backstage by the Mean Street Posse. Kane received a shot at the WWF Championship on December 20, but with the stipulation that, if he lost to incumbent Big Show, Tori would have to spend the Christmas weekend with X-Pac. Kane lost after the New Age Outlaws distracted him. Tori insisted upon her return, however, that X-Pac had been a perfect gentleman. Around the same time, Tori began to become paranoid, and grew hysterical after Test hugged her. Kane promptly destroyed Test in the ring, believing Tori's claims that he had harassed her. Other wrestlers began to exploit Tori's neuroticism, using it to unleash Kane on their enemies. This included Mankind, who manipulated the duo into attacking a fake Mankind hired by Triple H, and Chyna, who manipulated Tori to get Kane to attack Chris Jericho.
Kane continued to feud with X-Pac, and on January 27, 2000 he was ambushed in the ring by the McMahon-Helmsley Faction when tricking him into joining DX, X-Pac's allies. After tying Kane up, X-Pac revealed that Tori was now his girlfriend. Tori began accompanying X-Pac and his partner Road Dogg to the ring, becoming a member of the new D-Generation X in a brief heel turn. She helped X-Pac defeat Kane at No Way Out, but was unable to stop Kane from defeating him at WrestleMania 2000, and was also given a Stink Face from Rikishi during the match. Additionally, she helped Stephanie McMahon win the Women's Championship from Jacqueline in March. At the King of the Ring in June, Tori, X-Pac, and Road Dogg participated in a table and dumpster match against the Dudley Boyz that ended with the Dudleyz powerbombing her through a table. Tori was sidelined with a torn labrum on June 24. On the October 30 edition of Raw, Tori returned in a segment at WWF New York, confronting and slapping X-Pac due to the events at King of the Ring.
Tori returned in January 2001 as The Black Ninja, a masked villainess in a black bodysuit who helped Raven retain the Hardcore Championship. Raven's Hardcore title feud with Crash Holly led to a feud between The Ninja and Crash's on-screen cousin Molly Holly. Holly finally unmasked the ninja on the March 11, 2001 episode of Sunday Night Heat, revealing her to be Tori. Subsequently, she was removed from television.
After working as a trainer on WWF Tough Enough throughout the summer of 2001, Tori was released by the WWF in September 2001.