What wrestler that was supposed to be a feared monster did you think was the biggest joke? If I live to be 100, I don't think I'll ever see anything that tops the Yeti in WCW circa 1995 coming out at Halloween Havoc and dry humping everyone. A distant second would have to be Mantaur in the WWF from 1994-1996.
Mantaur was never actually supposed to be anything. That was mostly a rib on Jim Cornette as best as most people can tell. I feel like King Mabel in 1995 was one of the worst examples of monster because no one took him seriously and he helped destroy Diesel's chances of getting over in that Hogan role they wanted so badly.