Maisie Williams, best known for her role as Arya Stark in the hit HBO show "Game of Thrones," has been confirmed to join the cast of "X-Men" spin-off "New Mutants."

The Hollywood Reporter, which first confirmed the news, also said that Anya Taylor-Joy, who starred in "The Witch" and "Split," will also be part of the film. Williams will be playing the role of Wolfsbane, who has the ability to transform into a wolf. Taylor-Joy, meanwhile, will play Magik, the sister of X-Men member Colossus, who has sorcerous powers and is able to travel through great distances using teleportation discs.

The publication also said that the film will feature the "angst-driven" adventures of teenage mutants. The "New Mutants" script writers are Knate Lee and Josh Boone, who will also be the director of the movie. Simon Kinberg and Karen Rosenfelt will serve as producers. The film is set to start production in July.

It also said that the production team is making a serious effort to look for a native American actor to play Danielle Moonstar, and a South American for the role of Sunspot. Also slated to be part of the mutant lineup are Cannonball and Warlock. Professor X, played by James McAvoy, has earlier been reported to be part of the cast, but this has yet to be confirmed by Fox.

Rumors that Williams and Taylor-Joy are involved in the project have been going on since 2016. However, it is only now that this has been confirmed. Boone has been reportedly courting the two to join the cast, but he was only able to get them officially on board after "New Mutants" was officially greenlit by the studio.

Williams will be the second Stark who will be joining the Marvel family. Sophie Turner, who plays Sansa on "Game of Thrones," plays Jean Grey in the rebooted "X-Men" film series.

"New Mutants" is slated for release on April 13, 2018.