The Road Warriors immediately signed with the World Wrestling Federation (WWF) in 1990 and were pushed into a feud with the most famous of all “Road Warrior Clones”, Demolition, a group which included their old training partner Barry Darsow. Due to the ailing health of one of Demolition (Ax) he was replaced by Crush but the magic of the original Demolition was gone and the feud did not live up to the high hopes of the fans.
Just over a year after signing with the WWF, the Legion of Doom won the WWF World Tag Team Titles and held them for about 8 months. When they lost the titles, they briefly left the WWF, only to return with long time manager Paul Ellering by their side, as well as a wooden ventriloquist dummy called “Rocco”. Both members of the L.O.D. thought the Rocco gimmick was stupid, and it led to Hawk walking out of the WWF immediately following Summerslam 92, leaving Laurinaitis on his own for the first time in 9 years. Being a businessman, Animal went ahead and finished his contractual obligations with the WWF, as a singles wrestler and occasionally teaming with former rival Crush, formerly of Demolition. During a handicap match in Japan against the Beverly Brothers in September 1992, Laurinaitis legitimately injured his back from a botched double suplex and had to take a lengthy hiatus.
After returning to the WWF, the Legion of Doom took part in the Stone Cold Steve Austin vs. the Hart Foundation feud, siding with Austin against the Harts. The Legion of Doom also became 2 time tag team champions on October 7, 1997 when they defeated The Godwinns. In November 1997, the Legion of Doom faced the newly formed New Age Outlaws (Road Dogg and Billy Gunn) and lost the titles to the upstart team.
After several unsuccessful challenges the L.O.D. were repackaged as Legion of Doom 2000 with manager Sunny, although she did not stay with the team for long. At the same time, Paul Ellering returned, but sided with D.O.A., whom L.O.D. were feuding with at the time; Ellering and Animal explained on the Road Warriors DVD that it was hard for Ellering to work with another team against the Road Warriors and difficult to rip on his former team on promos.
In 1998, the Legion of Doom became involved in their most controversial angle, playing off Hegstrand’s real life drug and alcohol problems. Hawk started to show up drunk or “unable to perform” on TV. As Hawk proved more and more erratic and unreliable, a third L.O.D. member, Puke, was introduced to team with Animal while Hawk dealt with his personal issues. The storyline ended with accusations that Puke had been the "enabler" of Hawk's problems, exploiting them to take Hawk’s place in the team. During the controversial segment, Hawk was shown to have fallen off the Titan Tron. Neither Hawk nor Animal approved of the WWF exploiting Hawk’s personal problems, which caused them to subsequently leave the WWF.
While the Road Warriors never officially broke up, Animal started making an increasing number of solo appearances after they left the WWF as Hawk struggled with drug and alcohol addiction.
Animal and Hawk made a surprise appearance on RAW on May 12, 2003 when they took on Kane and Rob Van Dam for the World Tag Team Championship. Although Hawk and Animal came up short in their attempt to become three-time champions, it was clear that Hawk had defeated the demons that had once kept him from competing, and the Road Warriors had hopes of returning to WWE. However, Hawk died on October 19, 2003.
Animal made a return to WWE on the July 14 episode of SmackDown! in 2005, where he was challenged by the then-WWE Tag Team Champions MNM to a title match at The Great American Bash. Finding a new tag team partner in Heidenreich, Animal went on to defeat MNM for the titles, dedicating the win to Hawk by saying, "Hawk, this one was for you, brother!" The two would team up for a few months in a new chapter of the Legion of Doom, with Heidenreich adopting the L.O.D.'s shoulder pads, face paint, and mohawk haircut. However, this came to an end with Heidenreich's release from WWE on January 17, 2006.
On the March 3, 2006 episode of SmackDown!, Animal teamed up with Matt Hardy to face MNM. After he and Hardy lost the match, Animal turned heel for the second time in his career by attacking and injuring Hardy's knee. Animal reasoned that he had realized that Hardy and Heidenreich were screw-ups and that Road Warrior Hawk was the only tag team legend and partner for him. After the heel turn, Animal, once again known simply as The Road Warrior, would drop many aspects of the well-known Road Warrior gimmick, losing the face paint, and shoulder pads. Animal's look at this time was similar to his old Road Warrior gimmick in the early 1980s he had prior to teaming up with Hawk.
In his final WWE appearance, Animal defeated Paul Burchill on the May 6, 2006 edition of Velocity. On June 26, 2006, Animal was released from his WWE contract.
WWE announced on March 28, 2011 on WWE Raw that the Road Warriors would be inducted into the 2011 Hall of Fame.
On the July 20, 2012 edition of WWE Friday Night SmackDown, Animal returned to face Heath Slater in honor of RAW's 1000th episode.