1) Uber-Reem - He was just an imposing figure in the octagon. You can blame it on Lesnar having bad guts, but he looked like he wanted no part of Uber-Reem. And you know what? I ain't mad at him for it.
2) Fedor - He doesn't look physically imposing at all, but that expressionless stare is super creepy. It's like a controlled rage.
3) Current Rumble Johnson - He wasn't scary at 170, but he is a monster at 205. Again, that controlled rage and explosion is scary.
4) JDS (prior to Cain beatings) - Dude was legit scary. Scary power, pretty good precision and accuracy. When leather connected, it was night night!!!
5) Mark Hunt/Roy Nelson - Both guys have the ability to do walk off KOs. And the fact that one of them did it to the other is even crazier! I wish I could punch someone hard enough that I could turn my back and just walk off while they fall lifeless to the ground.