Hafthor Bjornsson is best known for his role on Game of Thrones as Gregor "The Mountain" Clegane. Before that, Bjornsson gained recognition as a strongman, winning the last two Europe's Strongest Man competitions and finishing as high as second in World's Strongest Man. Early in 2015, the 6'9", 400-pound man broke a 1,000-year-old record by carrying a 32-foot, 1,433-pound log five steps. But if it weren't for a leg injury at age 20 in 2008, Bjornsson might not have ever become a strongman or a recurring character on one of the most popular television shows of all time. The man who would become The Mountain was a professional basketball player in his native Iceland, and he looked nothing like the mass of muscle we know today.