#4 Heidenreich
For some reason. WWE saw fit to give Heidenreich a massive push as soon as he made his television debut. His character wasn't particularly interesting and he was barely passable with his in-ring ability.
What happened next? WWE saw fit to put him in a high-profile singles match against The Undertaker at Survivor Series 2004. The match was terrible, mostly because of how terrible Heidenreich was at this point, and even Undertaker couldn't get him over.
A WWE Hall of Famer isn't a John Cena fan. More details HERE
#3 Mabel
Vince McMahon saw Mabel as the next top heel in the mid-'90s and it was a total disaster. Mabel was too limited in the ring and even a high-profile feud against The Undertaker following his loss to Diesel at SummerSlam 1995 wasn't enough.
Taker and Mable actually feuded for a while and it all eventually led to a casket match at In Your House 5 which lasted a paltry six minutes as Taker beat his larger opponent without breaking a sweat.
Mabel also injured The Undertaker, breaking his orbital bone with a legdrop. A number of others wrestlers also said Mabel was unfair to work with and this led to his departure in 1996.