With filming currently underway, news for the fourth season of HBO's hit show "Game of Thrones" is slowly leaking out, and WinterIsComing.net has reports on some of the latest casting developments.

In villian news, HBO has confirmed that the character of the Mountain has been recast, and Icelandic strongman Hafþór "Thor" Björnsson will take on the role of Gregor Clegane, originally played by guest star Conan Stevens in the season 1 episode, "Cripples, Bastards and Broken Things."

While 24-year old Björnsson has no acting experience to his credit, his imposing 6'9'' frame will surely make a impact on-screen. Not to mention, he has already won the title of "Iceland's Strongest Man" for the last three years in a row, having placed third in the 2012 "World's Strongest Man" competition.

There is no word yet on whether or not we will hear Gregor Clegane speak in the upcoming season, or whether or not his face will be concealed by his helm most of the time.

According to IndieWire bog Shadow and Act, Angolan actor Hoji Fortun has joined the "Game of Thrones" family, though his role has been kept top secret for now. The actor, who has mostly worked in African and Portuguese cinema, has been teasing fans on Twitter and Facebook that he will soon be heading to Croatia to film, which means he will either be involved in the King's Landing or Daenerys storyline.

WinterIsComing.net speculates that he will play sellsword Brown Ben Plumm, whom Dany encounters during her travels. The possibility also stands that he could play a newly created character that did not appear in the source material, "A Song of Ice and Fire."

On Aug. 28, filming in Croatia began, and photographs were taken of Natalie Dormer, Gwendoline Christie, and Dame Diana Rigg in the scene set to be the first in the first episode of season 4.

Click here to see photos of filming in Croatia of the first scene, as well as pictures of the actors who are reportedly new additions to the "Game of Thrones" cast.