Poffo went to the World Wrestling Federation and made his debut on July 13, 1985 episode of WWF Championship Wrestling. Teaming with Pedro Morales, the duo defeated J.A. Rizzo and Barry O in a match taped in Poughkeepsie, New York. While Lanny was not a headlining WWF star like his brother, Randy Savage, he initially built a niche for himself wrestling as a babyface. In his first role as Leaping Lanny Poffo, he would bring frisbees to the ring, read a short poem written on one of them that he himself had penned, and then throw the frisbees into the crowd. Each poem typically ridiculed the heel who he was about to wrestle, or built heat in favor of the face with whom the heel was feuding at the time.
Lanny was initially undefeated in WWF competition, rolling off victories against Mr. X, Rene Goulet, Terry Gibbs, Barry O, and Moondog Spot. However he suffered his first defeat on July 27 edition of Championship Wrestling, teaming with Keith Diamond in a loss to The Iron Sheik and Nikolai Volkoff. This presaged a series of losses to Jesse Ventura, Big John Studd, and The Missing Link. During his early career in the WWF, he was not a main-eventer and wrestled primarily as enhancement talent on television shows. However, rather than being squashed like most jobbers at the time, he displayed a greater amount of offense in his matches. He found great success on house shows, where he continued to defeat other undercard wrestlers. Poffo performed an agile, athletic, high-flying style at a time when big, heavy power wrestlers still dominated the promotion.
He made his first Saturday Night's Main Event appearance on October 5, 1985, when he recited a poem at the wedding of Uncle Elmer. Entering 1986, he continued to be highly competitive against lower-level opposition, reeling off considerable house show or televised victories against Terry Gibbs, Barry O, Rene Goulet, Tiger Chung Lee and SD Jones. However, he remained less successful against the upper tier of the roster and sustained losses to Hercules and Jim Neidhart. He also is noted for competing in a battle royal on Saturday Night's Main Event X in Detroit in 1987, where he was headbutted and eliminated by André the Giant, causing him to bleed heavily all over the floor and have to be carried out on a stretcher.
In February 1987, he helped to participate in another famous angle, teaming with The Can-Am Connection in a match against Adorable Adrian Adonis and The Dream Team. During the match, Adonis accidentally cut the hair of Brutus Beefcake - an angle that would ultimately lead to the latter's face turn and assumption of "The Barber" gimmick. Poffo and the Can-Ams won this WWF Superstars of Wrestling match by disqualification.
In January 1988, Lanny defeated Sika the Savage Samoan in a series of upsets, and during the following month he began a lengthy house show series with the newly heel-turned Dan Spivey. Poffo continued to receive a strong push against lower level competition like Barry Horowitz, but was unable to break through as a top tier member of the roster. He entered a house show series with Jim Neidhart following the temporary dissolution of The Hart Foundation, but was unsuccessful in these contests. His fortunes changed somewhat later in the summer when he feuded with "Dangerous" Danny Davis on the house show circuit, pinning Davis on multiple occasions. Entering the fall of 1988, he faced numerous preliminary opponents and embarked on a lengthy winning streak, defeating Barry Horowitz, Sandy Beach, and George Skaaland. He continued to compete against opening card talent for the remainder of the year and was largely successful.
However, as he entered 1989, his fortunes began to wane. Poffo began the year with a loss to Iron Mike Sharpe at a house show on January 1 in West Palm Beach, Florida, and this was followed by a televised defeat on January 13 in Boston, Massachusetts to The Brooklyn Brawler. After a smattering of wins, he then lost to Conquistador Uno on February 20, 1989 in Worcester, Massachusetts. These were followed by a pair of defeats to Tim Horner in March 1989. Now approaching his fourth anniversary of his WWF tenure, Lanny Poffo found himself at a career crossroads.
On March 18, 1989, still known as "Leaping" Lanny Poffo, he turned heel and berated the local Boston sports teams, insulting them in his poetry, and instantly drew heat from the Boston crowd. Poffo was subsequently re-introduced as The Genius, a highly intelligent, arrogant heel who wore an academic cap and gown to the ring. After weeks of giving poetry as The Genius, he had his debut against Sonny Rodgers and defeated him. His poems now ridiculed the face wrestlers, and he adopted an exaggerated effeminate, showboating manner to draw heat from the crowd. During his matches, the Genius would often write a mathematical equation on a clipboard that would "tilt the balance of the match in his favor". Poffo began a house show series against Jim Powers that spring and embarked on a lengthy winning streak. That summer who moved on to feud with Powers' former The Young Stallions partner Paul Roma and was also victorious. His first pinfall loss under his new heel persona finally came on August 12, when he was defeated by Koko B. Ware at a house show in Richfield, Ohio.
Aside from the one untelevised loss, Poffo remained undefeated. He was featured on WWF Superstars during the coronation of Randy Savage as the new "King of the WWF"; Lanny read the proclamation for his brother. He continued to win in his house show series with Koko B Ware and at the same time began to serve as "executive consultant" (and occasional tag team partner) for Mr. Perfect.
On the November 25, 1989 Saturday Night's Main Event XXIV, The Genius faced WWF World Heavyweight Champion Hulk Hogan and spent much of the match taunting Hogan and drawing heat from the crowd with his absurd antics. Several minutes into the match, Mr. Perfect appeared at ringside where he goaded Hogan and defaced the championship belt by sticking chewing gum on it. Poffo then tricked Hogan into following him outside the ring, resulting in Mr. Perfect striking Hogan with the championship belt and Poffo climbing back into the ring to win the match by countout. Later in the show, Mr. Perfect and Poffo destroyed the stolen belt with a hammer. This marked the first time in several years that Hogan had sustained any form of defeat on WWF television.
Poffo entered 1990 firmly entrenched as a main roster player. He suffered his first televised defeat when he teamed with Mr. Perfect in a losing effort against WWF World Champion Hulk Hogan and Intercontinental Champion The Ultimate Warrior on the January 29 episode of Prime Time Wrestling. That winter, he entered a house show series against Jim Neidhart and was generally victorious there as well. Poffo made his first pay-per-view appearance at the 1990 Royal Rumble and wrestled Brutus Beefcake to a double disqualification after "The Barber" began cutting his hair and Mr. Perfect interfered.
In March, his momentum began to cool as Poffo began suffering house show defeats to Jim Neidhart. He also teamed with Perfect in losing efforts against Hulk Hogan and various partners. At WrestleMania VI, he had his hair cut by Brutus Beefcake after Mr. Perfect was pinned. Shortly after WrestleMania VI, Bobby Heenan became Mr. Perfect's manager. In the meantime Poffo was programmed into a feud with Brutus Beefcake and took to wearing wigs and amateur wrestling headgear to cover the haircut that "The Barber" had given him.
By the summer of 1990, Poffo had lost his feud with Beefcake and started to move back down the card. In June, he renewed his house show series with Koko B. Ware; this time "The Birdman" dominated on shows around the country. The feud continued through the summer and achieved national visibility on the August 27, 1990 edition of Prime Time, where Ware defeated The Genius on television. Poffo made a guest appearance on the October 13, 1990 episode of Saturday Night's Main Event XXVIII, participating in Oktoberfest activities along with The Hart Foundation, Jim Duggan, Mr. Fuji, and The Orient Express. That winter, he engaged in opening match contests with Dustin Rhodes, Shane Douglas and Jim Brunzell.
After being on sabbatical for several months, Poffo returned with a flurry in April 1991, wrestling Greg Valentine, Jim Duggan, and Bret Hart. On June 26, 1991 he scored a major upset victory in his comeback when he defeated Jim Duggan at a house show in Lansing, Michigan. On the September 7, 1991 edition of WWF Superstars, he became the manager of The Beverly Brothers (Beau and Blake). Unlike during his time as manager of Mr. Perfect, Poffo generally remained on the sidelines for much of the remainder of 1991 and wrestled very sporadically.
In December 1991, Poffo teamed with The Beverly Brothers in six-man matches against The Bushwhackers and Jim Neidhart. At the 1992 Royal Rumble, the Genius managed The Beverly Brothers to a win over The Bushwhackers. He also continued to occasionally wrestle, and picked up a televised win over Brian Costello on the July 6 episode of Prime Time Wrestling and wrestled house show matches against Jim Brunzell, Virgil, and Bob Bradley. On the August 28 edition of Prime Time, he teamed with the Beverly Brothers in an unsuccessful effort against The Legion of Doom and Paul Ellering. At SummerSlam 1992, Poffo's charges were thwarted in their challenge of The Natural Disasters for the WWF Tag Team Championship; he continued to manage them until making his final appearance at the 1992 Survivor Series.
After a nineteen-month absence, Poffo returned in May 1994 and defeated Koko B. Ware on two house shows in Florida. His final WWF match was a loss to Mabel on June 11 at an event in Richmond, Virginia.
Poffo signed a World Championship Wrestling (WCW) contract in 1995, but wrestled only once during his time there before leaving.
On March 28, 2015, Poffo returned to WWE at the 2015 Hall of Fame induction ceremony to induct his deceased brother, Randy Savage. Poffo read poems and shared memories about his brother's past. The following day, Poffo shared the stage with other 2015 Hall of Fame inductees at WrestleMania 31, representing his brother.
Poffo passed away on February 2, 2023.