2. Muhammad Hassan
https://www.youtube.com/watch?v=2ZGC6b4eP8Q Before Henry or Khali, Undertaker had faced off against Muhammad Hassan in 2005. This feud was built on very poor taste, essentially playing on the fear of terrorism in the post 9/11 world. Hassan was a Muslim character who riled against America as oppressors, creating a controversial storyline which played on terrorist stereotypes. The feud was put way over the top during a Smackdown taping which aired the same week as the London Bombings. This angle involved Hassan leading a group of masked terrorists in beating up The Undertaker and choking him with chicken wire. It was considered so shocking that UPN decreed to WWE that they could never feature Hassan on Smackdown again. This necessitated WWE to write Hassan out of the shows... which they did by having Taker 'kill' Hassan in their match at The Great American Bash. Undertaker did this by giving Hassan the last ride through the stage and straight to hell. For being a feud which involved The Undertaker 'killing' a muslim named Muhammad on a show called the 'Great American Bash' this was very delicate and insensitive ground indeed for WWE... the feud was plain bad taste and could have generated grave consequences in stirring heated sentiments of the time.