15A Familiar Face
From his appearances in several films, like Guardians of the Galaxy and Age of Ultron, we've gotten a glimpse here and there of his terrifying and booming voice and persona. While we’ve gotten to know who Thanos is and how he thinks, not many people know the man behind Thanos.
In fact, the actor who plays Thanos might be someone you already know.
The original actor for Thanos was actor and stuntman Damion Poitier, who could be seen playing the role of the villain in the post credits for The Avengers. Poitier has since been replaced by another actor who is better known, that actor being Josh Brolin. Brolin has been known for his roles in movies such as Gangster Squad, Sin City: A Dame to Kill For, Inherent Vice and his first acting role in the cult classic The Goonies. As of now, Brolin not only does the voice of Thanos, but he also does the motion capture for him too.
Brolin does a great job at making Thanos quite intimidating as well as keeping to himself, making the character appear as if the Mad Titan has other things on his mind... more sinister things.