One of "Game of Thrones'" most feared men "The Mountain" proves to be physically strong no only in Westeros, but also in real life. The new Mountain, Hafþór "Thor" Júlíus Björnsson, made his first debut on GoT's "Mockingbird" episode last Sunday night. Hafthor Bjornsson is set to act as Cersei Lanniser's (Lena Headey) champion in Tyrion's trial-by-combat.

Hafthor Bjornsson stands 6"9 ft, weighs 419 pounds, and is just 25 years old. Bjornsson who hails from Iceland, is just one of the many strongmen in their country who regularly participates in strength competitions. Due to his massive physique and strength, reports say he consumes a daliy 10,000-calorie diet when he is training. He is the third recast for The Mountain in GoT and he just made his first appearance on Sunday night's episode.

Last year, Indianapolis Colts owner Jim Irsay even planned on signing the Icelandic giant to his team before the NFL Draft. Bjornsson declined the offer because, "Unfortunately, knee injuries have derailed Bjornsson's attempts to play contact sports. Randall J. Strossen of IronMind.com reports that the Icelandic giant played basketball before blowing out his knee and switching to weightlifting and strength competitions," reported Bleacher Report.

Bjornsson, having knee injuries resorted to another career and sport. He proved his overwhelming strength on and off screen as he recently joined the "World's Strongest Man" this year. "Björnssonj was 0.44 seconds away from winning the overall competition and settled for second place. He finished third place in 2012 and 2013," reported USA Today's For The Win.

During pre-taping of GoT's season 4, Bjornsson was seen in videos doing strength-training workouts in preparation both for the show and the Strongman competition. Bjornsson's strength was very notable that he appeared in several videos making new World Records.

Watch some of The Mountain's videos below.

CREDIT: Huni/YouTube

CREDIT:MrNorthernben's channel/YouTube

That giant dude from GoT is an actual Icelandic World's Strongest Man contestant. Hafthor Julius Bjornsson. pic.twitter.com/SJHWsRARPP — Mark Armstrong (@ArmstrongABC11) May 19, 2014