Muhammad Hassan (real name Mark Copani) had a brief but memorable run in WWE as an Arab-American heel who was angry about the prejudice he faced after 9/11. Before a controversial segment ended up killing his career, this guy was being pushed to the moon. On his very first appearance, he got to interrupt Mick Foley. He wasn't even on TV for a year, and he got wins over various wrestling legends (including Sgt Slaughter and Jerry Lawler), a WWE title match, feuds with three of the greatest wrestlers of all time (Hulk Hogan, Shawn Michaels, and The Undertaker), and a win over then-WWE World Heavyweight ChampionBatista (it was by disqualification, but a win's a win).Under his previous ring name of Mark Magnus, he was a 1x OVW Heavyweight Champion.The Other Wiki has a more detailed rundown on his life and (very brief) career.
Early-Installment Weirdness: Wrestled in WWE's developmental promotion Ohio Valley Wrestling as "This Year's Model" Mark Magnus and looked VERY different from how he looked as Hassan.
Enemy Mine: When he entered the 2005 Royal Rumble, the eight other men already participating in the Rumble immediately stopped fighting and ganged up on him to eliminate him. This approach is usually reserved for the Mighty Glacier/The Giant-type of wrestlers (André the Giant, Earthquake, Yokozuna, etc.), since it would be necessary to have a bunch of guys team up to eliminate them), not a 243 lbs. normal-sized wrestler such as Hassan, who could have been tossed at any time by anyone.
Hassan was also part of a different enemy mine. During Triple H's feud with Batista, Batista had a lumberjack match with an opponent Triple H selected (Kane), and Hassan was one of the lumberjacks. When Ric Flair was motivating the lumberjacks by telling them about how Batista screwed them all (each lumberjack had previously suffered a loss to Batista), he mentions Hassan and "whatever country you come from".
Flanderization: Towards the end of his run, he slowly began to act more like a terrorist, even though the point he was trying to make was that he was not a terrorist.
Foreign Wrestling Heel: Inverted. His character was born and raised in the United States, and the main part of his gimmick was that he was fed up with people treating him like one of these post-9/11. He was portrayed as a villain because of this.
The fans would chant "USA" whenever he was in the ring, regardless of who he was confronting. This was particularly humorous when he interrupted Chris Jericho's Highlight Reel, and the crowd still chanted "USA". Hassan was American, and Jericho is Canadian (he was born in America, but was raised in Canada and identifies as Canadian). Therefore, the crowd was unintentionally cheering for Hassan.
Mean Character, Nice Actor: In contrast to Muhammad Hassan's outspokenness and willingness to attack anybody who disrespected him, Mark Copani is very mild-mannered and cited his not wanting to offend anybody as one of the reasons why he would not want to return to wrestling.
The Revolution (led by Doug Basham and also featuring Damaja [WWE's Danny Basham], Rob Conway, Big Bad John [Heidenreich], Mike Hardnote Mike Howell, aka ECW/TNA's Jack Dupp or Mike Maverick in TheHardyz' OMEGA promotion, Kanyon, Queen Victoria and Jackie Gayda.)
The Team Players (led by Johnny Ace and featuring Inspector Max Impactnote Matt Wiese, aka WCW's Horshu/WWE's Luther Reigns, Rob Conway, Nick Dinsmore and Chris Masters).
Real Life Writes the Plot/Screwed by the Network: After a now infamous segment in which Hassan came down to the ring with several men wearing ski masks, which coincidentally aired on the same day as the 2005 London bombings (although it was taped beforehand), UPN demanded that WWE keep Hassan off of TV. This led to him losing his match with The Undertaker at the Great American Bash and getting the Last Ride through the stage as a way to "kill off" the character.
Reclusive Artist: Ever since retiring, he has mostly stayed out of the public eye. He did, however, attend a wrestling convention in 2010 and he worked with Shad Gaspard (formerly of Cryme Tyme) on a graphic novel.
Short-Lived Big Impact: Not counting his time in OVW, his career in WWE lasted from December 14, 2004 to July 24, 2005. Seven years later, he still has a small but dedicated fanbase and pretty much every YouTube video that features him has countless comments with variations of the phrase "I want him to come back."