Snow began working for the World Wrestling Federation (WWF) when he signed a contract in August 1995. He wrestled under numerous gimmicks in the WWF, such as Avatar (a superhero gimmick with Snow putting on his mask right before starting a match) and Shinobi, a "ninja assassin" hired by Jim Cornette to dispose of Shawn Michaels. Snow's WWF debut took place on the October 23, 1995 episode of Monday Night RAW as Avatar. He also competed in and lost a match against Marty Jannetty under the name Steve Moore. Snow received his first mainstream exposure with the WWF as Leif Cassidy, the heel tag team partner of Marty Jannetty. The duo was promoted as The New Rockers, a throwback to the original Rockers team of Shawn Michaels and Jannetty. Eventually, the storyline was dropped, and Snow was reduced to jobbing for mid-carders. He left soon after.
Snow was recalled to the company in 1998, where he adopted the gimmick of talking to "Head", a fake mannequin head, creating some of the more memorable humorous skits of "The Attitude Era" including fighting himself in a hardcore match (which he won by putting himself through a table) and his short lived comedy tag team with Steve Blackman.
During the summer of 1999, at the conclusion of a storyline where Head was impaled with a spike by Prince Albert, Snow replaced Head with a chihuahua named Pepper, who he claimed talked to him. A variety of segments were broadcast showing Snow's interactions with the dog, including bringing Pepper to the ring to either "participate" in matches or be held by the broadcast team. This led to a storyline where Big Boss Man kidnapped Pepper. Boss Man agreed to return the dog if Snow defeated him in a match for the Hardcore title; however after losing the match he reneged and kept the dog. Later, in a segment on SmackDown, Boss Man invited Snow to his hotel room to discuss the situation, before serving Snow dinner which was then revealed to be Pepper. The feud culminated at a "Kennel from Hell" match at Unforgiven, which consisted of a regular cage which was surrounded by a Hell in a Cell structure, with "a trained pack of wild dogs" in between the two, and the objective was to escape both cages without being attacked by the dogs. Al Snow won the match.
Snow would later team with Mick Foley, but turned heel by betraying him. He would later turn face again due to fan reaction. Snow was often the butt of Foley's jokes during Foley's tenure as the Commissioner in 2000.
In early 2000, he began to team with Steve Blackman as an "odd couple" tag team called Head Cheese. Also in 2000, Snow won the European Championship from Perry Saturn. He then began a tongue-in-cheek gimmick of entering the ring to various European countries' native music, with his theme song sung in the language of the country, and wearing attire which would suit the stereotype of that country. This continued until he lost the title to William Regal.
In 2001, Snow tried to rally support from the fans to vote for him as the new Commissioner of the company following Foley's on-screen firing by Vince McMahon in December 2000. By March 2001, a match was set up between Snow and Regal to determine the new Commissioner, which resulted in Regal winning. Snow then took some time off from the ring in order to commit more time for the reality show Tough Enough. He made his return to the ring in October 2001 during the InVasion era and challenged Christian for the European Championship at Survivor Series, which he lost.
Snow's last championship reign came on March 11, 2002, when he defeated Goldust to win his last Hardcore Championship. He lost the title to his former Tough Enough student, Maven, a few days later. He was drafted to SmackDown! as part of the 2002 Brand Extension, where he teamed up with Maven. After taking time off again for another season of Tough Enough, Snow returned as a member of the Raw roster and eventually became a commentator for Sunday Night Heat alongside Jonathan Coachman. When the Coach sided with Eric Bischoff, Snow followed suit, turning heel. The two feuded with Jim Ross and Jerry Lawler, and briefly replaced them at the Raw announce table after a victory at Unforgiven in 2003. When Tough Enough IV came to SmackDown!, Snow was on the scene and turned face once again.
In 2006, Snow returned to wrestling full-time as a member of the new ECW brand. His first appearance in the new brand was in the WWE vs ECW Battle Royal at the "WWE vs. ECW Head to Head" special, where he was accompanied by Head. He was eliminated from the match. On the June 13, 2006 debut of ECW on Sci-Fi, Snow participated in an Extreme Battle Royal, which was won by Sabu. Over the next six months, he was used sporadically, mostly as a jobber, losing to people such as Test and Kevin Thorn.
On January 18, 2007, Snow was released from his WWE contract, along with several other superstars. On Raw XV, the 15th-Anniversary special on December 10, 2007, Snow participated in the 15th Anniversary Battle Royal.