Daivari signed a contract with World Wrestling Entertainment in August 2004 and debuted on October 19, 2004, on Raw alongside Muhammad Hassan as "Khosrow Daivari". Their gimmick was that of two Arab-Americans who were tired of the prejudice and racism they were receiving after the 9/11 attacks. In the weeks leading up to their debut, the two men would appear on Raw in vignettes promoting their hatred towards "America". In the following weeks, they would back up their words with actions, initiating a feud with Raw announcers Jim Ross and Jerry "The King" Lawler. At WrestleMania 21 on April 3, 2005, Daivari and Hassan were involved in a storyline with returning WWE legend Hulk Hogan. While attacking injured wrestler Eugene, Hogan made his classic entrance and ejected both men from the ring to the delight of fans in attendance. Ironically, Daivari would scream instructions in Persian to Hassan when working as his manager, though this was often described as "Arabic" on broadcasts.
The following night on Raw, Daivari and Hassan interrupted Shawn Michaels during a promo. The two attacked Michaels and left him helpless in the ring. This led to Daivari's first singles match in WWE, on the April 11, 2005 edition of Raw. Although Michaels was heavily favored, Daivari, with help from Hassan, got the upset win. Enraged, Michaels demanded a match against both Daivari and Hassan. Raw General Manager Eric Bischoff refused to grant a handicap match but instead ordered Michaels to find a partner. That partner turned out to be Daivari and Hassan's WrestleMania foe Hulk Hogan.
On the April 18, 2005 episode of Raw, Michaels was once again double teamed by Daivari and Hassan until Hogan appeared to make the save. Hogan accepted Michaels' offer to tag and the match was set for the Backlash pay per view on May 1, 2005. At Backlash, Hogan and Michaels picked up the win which led to friction between the two since Hassan blamed Daivari for the loss. The next night on Raw, Hassan verbally and physically attacked Daivari leaving their future as a team in question.
Both Daivari and Hassan were later drafted to SmackDown! on June 23, 2005 as part of a package deal. On the July 7, 2005 episode of SmackDown!, GM Theodore Long put Daivari in a match that night against The Undertaker, and Muhammad Hassan in a match against The Undertaker at The Great American Bash. Daivari was squashed easily in that match, after which Hassan began to pray on the ramp, summoning five masked men to the ring. The masked men beat and strangled the Undertaker into submission, and Hassan put him in the camel clutch. Afterward, the masked men carried Daivari off like a martyr. At The Great American Bash 2005, after Hassan lost in a match with The Undertaker, Hassan was given the Last Ride through an open stage ramp onto a concrete floor. It was reported that he sustained serious injuries and had to be rushed to a nearby medical facility; this was an angle aimed to "kill off" the character, as it was garnering heat with the UPN network.
On November 7, 2005, Daivari returned to Raw, acting as Kurt Angle's anointed special guest referee in the tag team match between Shawn Michaels and John Cena versus Angle and Chris Masters. During the match, Daivari favored Angle and Masters, who won the match via disqualification when Michaels was caught with a chair Angle brought in.
On November 21, 2005, Kurt Angle announced that Daivari was to be the referee for all his future matches, including his match against WWE Champion John Cena for the title at the 2005 Survivor Series. Mr. McMahon rescinded that at the kangaroo court trial of Eric Bischoff on Raw on December 5, 2005. Daivari remained aligned with Kurt Angle as his manager.
On the January 13, 2006, edition of WWE Friday Night SmackDown!, Angle and Daivari jumped to SmackDown!, where Angle won the World Heavyweight Championship the very same night. Angle later revealed that his contract on Raw had expired, which allowed them to switch brands. Angle was already signed to face Shawn Michaels on Raw, however this non-title match went ahead, but Daivari would accidentally cost Angle the match against Michaels. Afterwards, Daivari and Angle argued, but when Daivari slapped Angle, he was Angle Slammed over the ropes and down to the floor on the outside of the ring. During the break on WWE.com Unlimited, an enraged Angle made it known that Daivari's services were no longer needed.
A short time later, Daivari faced his former client in a match. During the match, Mark Henry, the number one contender for Angle's title, attacked Angle. After the match, Daivari officially announced that he was now managing Henry and continued to manage Henry during his feud with The Undertaker. Daivari would disappear off television in the weeks leading up to WrestleMania 22 when, at WWE's Saturday Night Main Event, Daivari suffered a chokeslam and Tombstone Piledriver at the hands of The Undertaker onto the lid of a casket.
On the April 7, 2006 edition of SmackDown!, Daivari made his return bringing in the debuting The Great Khali to attack The Undertaker during his match with Mark Henry. The next week, Daivari officially presented him to the crowd, hyping him as an unstoppable monster. Over the following weeks, Daivari would accompany Khali to the ring as he destroyed various SmackDown! superstars. This would all lead up to a match with The Undertaker at Judgment Day on May 21, 2006, which Khali would end up winning. Daivari and Khali appeared as guests on Piper's Pit on the June 2, 2006 edition of SmackDown!, in which Piper made fun of Khali, who supposedly can't speak English. Eventually Piper stood on the bottom rope, attempting to match height with Khali, he managed to say: If this was twenty years ago, before Khali grabbed him by the throat. Daivari made Khali put Piper down and straitened Piper's jacket disrespectfully, Piper slapped Daivari, but was then given a chop by Khali. The Undertaker was the original guest on the Pit, but he declined the invitation a few days before. Daivari continued to accompany The Great Khali to the ring when Khali wrestled or attacked other wrestlers, but when The Great Khali became inactive due to injury, Daivari was taken off the road as well.
Daivari and The Great Khali were moved to the ECW brand officially when they made their ECW debuts on the October 31, 2006 edition of ECW on Sci Fi. Daivari beat "The Reject" Shannon Moore in a very quick match. Daivari's original theme music was used as well as his Persain rants on the microphone. Afterwards, Moore was manhandled by The Great Khali. Daivari continued his ECW winning streak over the next several weeks with The Great Khali usually following up the contest with a chokebomb on Daivari's opponent. At December to Dismember, Daivari got a victory over Tommy Dreamer following a schoolboy rollup. Dreamer then chased Daivari all the way to the back then, The Great Khali appeared and caught Dreamer, planting him on the steel ramp with a chokebomb. On January 8, 2007, The Great Khali debuted on Raw, without Daivari. The following night, however, Daivari accompanied Khali to the ring for his match with Dreamer on ECW.
Daivari returned to SmackDown! on February 9, 2007, defeating the Cruiserweight Champion Gregory Helms in a non-title match. He began wrestling in the Cruiserweight division. He was involved in a feud between Kane and The Great Khali once again promoting the Great Khali in March 2007. His first match against Kane, involved him being dragged backstage by Kane's chain and hook leaving his back with multiple bruises. A few weeks later, Daivari had a rematch with Kane and was again defeated.
Daivari returned to SmackDown! a few months later, teaming up with Chavo Guerrero and Jamie Noble against Jimmy Wang Yang, Paul London and Brian Kendrick in a losing effort. On the June 15, 2007 episode of SmackDown!, Daivari competed in a Fatal Four Way number one contenders match for the WWE Cruiserweight Championship, which he lost to Yang and also involved Shannon Moore and Noble.
Daivari was drafted back to Raw in the Supplemental Draft on June 17, 2007. He re-debuted on the June 18, 2007 edition of Raw, losing to Jeff Hardy. On the July 30, 2007 episode of Raw Daivari was defeated by Cody Rhodes who had to win his match or face being fired from WWE. Daivari's losing streak continued when he failed to win the position of General Manager of Raw by been eliminated early in the battle royal the week after Rhodes defeated him. Daivari then started to get on a roll on Heat (Raw's sister show) being victorious against Super Crazy and "Hacksaw" Jim Duggan. His return to Raw on September 17 saw him lose to Hacksaw Jim Duggan in a Flag match.
On October 16, 2007, Daivari was released from his WWE contract.