Sources confirm the villain's role in the new movie, and report that Brolin voices the character. Marvel teases Thanos in the post credits of The Avengers, but he hasn't appeared in trailers or promotional material.
Thanos is a godlike being who possesses superhuman abilities and telekinetic and telepathic powers. He is said to have a supporting role in the upcoming film, while main villain Ronan the Accuser (Lee Pace) runs the show.
Guardians of the Galaxy focuses on five unlikely superheroes: Peter Quill (Chris Pratt), Gamora (Zoe Saldana), Drax the Destroyer (Dave Bautista), Groot (Vin Diesel) and Rocket (Bradley Cooper). The movie debuts in theaters August 1.