Game Of Thrones fans know one character not to mess with is Gregor "The Mountain" Clegane — because he always finds a way to win, even if he has to literally crush his opponent's skull with his bare hands!
But is Hafthor Bjornsson, the third actor to play The Mountain on the HBO show, just as ruthless?
The hulking 6'9, 419 lb actor — and current World's Strongest Man (Europe) — put his muscles to the test when he faced off against World Armwrestling League Heavyweight Champ Devon Larratt in an old school arm wrestling match!
The ESPN pro arm wrestler is half Bjornsson's weight, so the match is pretty much the real life battle between The Mountain and The Viper. Don't worry, it has a way different ending!
Find out who wins in the video (below)!