Which "Big" Game of Thrones Role Has Been Recast for Season 4?

Game of Thronesis going through another recasting.

Hafthor Julius Bjornsson has been cast as Gregor Clegane, better known as the Mountain, the Icelandic actor announced on Twitter.

"For all my fans! I am happy to tell you that I will be the Mountain in Season 4 in Game of Thrones," he wrote on Tuesday.

Bjornsson replaces Ian Whyte, who replace Conan Stevens as the Mountain in Season 2. The Mountain will reportedly have a larger role in the upcoming fourth season.

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That's not the only recasting happening this season. Treme and Nashville star Michiel Huisman will reportedly replace Ed Skrein as Daario Naharis, a Tyroshi warrior who serves as a love interest for Daenerys Targaryen (Emilia Clarke).

Roger Ashton-Griffiths, who will play Mace Tyrell; Pedro Pascal, who will play the Red Viper; Indira Varma, who will play Ellaria Sand; Joseph Gatt, who is rumored to play Styr, the Magnar of Thenn; and Mark Gatiss, whose role is being kept a secret, will also join the cast.