He made his WWE TV debut on Raw as Muhammad Hassan on December 13, 2004 in an in-ring segment with Mick Foley after wrestling dark matches and house shows for about two months. His introductory video and gimmick featured him and his manager, Khosrow Daivari introducing themselves. He described himself as a Middle Eastern-American wrestler wanting relief from the increased stereotypes created by the 9/11 attacks, as he enters professional wrestling. He then concluded with a controversial extension of hands and praise to Allah. He stopped praising Allah vocally due to complaints by Muslim-Americans, but still extended his hands during his ring entrance. His speech followed by a supposedly Arabic translation of his speech (in truth Persian) by Daivari. Hassan's gimmick also involved him interrupting promos by other wrestlers with his theme music and approaching the ring to cut promos of his own, typically complaining about being held back due to anti-Arab prejudice. On a side note, Hassan's entrance theme became a meme, due to it being heavily featured on YTMND, depicting various celebrities, politicians, and fictional characters accompanied by Hassan's image and/or entrance theme to create the impression that these pop culture icons had been interrupted by Hassan's entrance; the name "Hassan" is now used as a slang term meaning "to interrupt."
Making his entrance into the WWE, he berated the way the media have characterized Arab-Americans after September 11. As an example, he focused his anger on Raw announcers Jerry "The King" Lawler and Jim Ross. He then defeated Jerry Lawler in his debut at New Year's Revolution. In the course of his undefeated streak, Hassan defeated wrestlers such as The Hurricane, Sgt. Slaughter, Chris Benoit , and Chris Jericho.
Hassan had attracted much heat as a heel, a fact which was evident at the 2005 Royal Rumble, in the Rumble match itself. When Hassan entered at number 13, everyone who was in the ring at the time: Chris Benoit, Chris Jericho, Edge, Shelton Benjamin, Booker T, Eddie Guerrero, Rey Mysterio, and Luther Reigns immediately ganged up on Hassan and eliminated him. Notably, Reigns and Edge were also heels at the time.
At WrestleMania 21 on April 3, 2005, Hassan and Daivari were featured in a segment with Hulk Hogan that saw Hogan coming to the rescue of wrestler Eugene who was being attacked by the two Middle Eastern performers. The next night on Raw, Hassan and Daivari came out to confront and assault fan favorite Shawn Michaels. The following week, Michaels approached Raw General Manager Eric Bischoff demanding a handicap match with Hassan and Daivari. Bischoff refused but did tell Michaels to find a partner and he would grant a match. Michaels then made a plea for Hulk Hogan to come back and team with him. On the episode of Raw, Hassan again led an attack on Michaels until Hogan appeared to save Michaels and accept his offer.
At the WWE Backlash pay-per-view Hassan and Daivari lost to Hogan and Michaels, with Daivari being pinned. Hassan would blame and attack Daivari for the loss the next evening on RAW.
On , 2005, Hassan faced popular World Heavyweight Champion Batista and won by disqualification, in the biggest match of Hassan's career. However, he and Daivari were beaten by Batista after the match.
The next week, Hassan was granted a 2-on-1 Handicap Match with Daivari for the Intercontinental Championship against Shelton Benjamin after threatening Raw General Manager Eric Bischoff with a lawsuit for Batista's actions. After Hassan initially appeared to pin Benjamin and win the title, the referee realized Benjamin was on the ropes and reversed his decision. Benjamin eventually pinned Daivari to retain his title.
On , Hassan and Daivari interrupted a promo by WWE Champion John Cena to complain about how Hassan was "screwed" out of the Intercontinental Title; Bischoff took the opportunity to punish Cena by booking him against Hassan in a WWE Title defense. Hassan's losing streak in title matches continued as Cena dominated him in a two-minute squash match, pinning him cleanly and thus ending his "unpinned" streak.
On the , 2005 episode of SmackDown!, it was revealed both Hassan and Daivari were drafted to SmackDown! in the 2005 WWE Draft Lottery. Hassan's move to SmackDown! would spell the beginning of Hassan's most famous and infamous few weeks, but also the end of Copani's WWE career. Hassan won his first SmackDown! match, a match against the Big Show with help from Big Show's rival Matt Morgan. The following week, Hassan was involved in a confrontation with The Undertaker.
On the episode of SmackDown! taped on July 4, General Manager Theodore Long put Muhammad Hassan in a match against The Undertaker at The Great American Bash and placed Daivari in a match that night against the Undertaker. Daivari was defeated easily, but Hassan began to "pray" on the ramp, summoning five masked men, dressed in black shirts, ski-masks, and camo pants. Armed with clubs and a piano wire, they beat and choked the Undertaker out, and Hassan put him in the Camel Clutch. Afterward, the masked men lifted Daivari above their heads and carried him away. Three days later, hours before the episode was scheduled to air, the London bombings took place. Without sufficient time to properly edit the segment out of the show, UPN showed the footage unedited in the United States and on The Score in Canada with an advisory warning shown several times during the broadcast. It was removed from the Australian and European (including in the UK) broadcasts.The angle elicited national attention in the New York Post, TV Guide, Variety, and other major media outlets. In response to the criticism, UPN decided that it would monitor the storyline closely and that it did not want the Hassan character on its network that week. Hassan later delivered a promo to the live crowd for the July 14 airing of SmackDown!, but when UPN announced that the segment would be edited, WWE decided to host the video of the segment on its official website. In the segment, Hassan, reiterates that he is an Arab-American and that the American people automatically and unfairly assume that he is a terrorist. Despite being in character, he referred to the real-world media coverage of the storyline, singling out the New York Post's Don Kaplan by name, and denouncing his description of the events on SmackDown!, such as Kaplan's comment of the masked men being "Arabs in ski masks". On the July 14 episode of SmackDown!, Hassan's absence was explained by a statement delivered by his lawyer, which said that Hassan refused to appear on the show until that month's Great American Bash due to the way he had been treated by the media and WWE fans.It was revealed in late-July 2005 that UPN had pressured WWE to keep Hassan off of their network, effectively removing him from SmackDown! However, Hassan had been booked as the winner in his number one contender's match against the Undertaker at The Great American Bash, setting up a Batista-Hassan match for the World Heavyweight Championship at SummerSlam. With no chance of having Hassan wrestle on SmackDown!, the Undertaker won the match instead. At the Great American Bash, after Hassan's loss, he was given the Last Ride through an open stage ramp onto a concrete floor where it was reported that he sustained serious injuries and had to be rushed to a nearby medical facility, apparently a solution aimed to end the Hassan character. Several days later, WWE.com hosted a video of a kayfabe announcement from Theodore Long, where he reiterates the stipulation that Hassan would no longer appear on SmackDown!.