-The Undertaker did not attend the Hall of Fame Ceremony at WrestleMania 21 because he wanted to protect his character, but also because he and Hogan have long standing backstage heat. Undertaker has been bitter towards Hogan from his days early on in WWE when he worked two straight PPV’s against Hogan. He heard that Hogan made a point of telling McMahon he wasn’t ready for a top spot at that point and claimed Taker didn’t protect him well during their matches including on a Tombstone piledriver.
Ever since then, he and Hogan have not gotten along. Many respected the Undertakers decision not to attend the ceremony. On that same note, some are saying that it took a phone call from Vince McMahon in order to persuade Steve Austin to attend the Hall of Fame Ceremony. There is also some heat between Austin and Hogan, but once Austin was there he seemed to enjoy himself and there are pictures of he and Hogan at the event speaking with one another.
-On another note, Undertaker is working with a bad hip and many say it’s only a matter of time before he will require surgery in order to heal himself.