Thanos is a fictional character portrayed primarily by Josh Brolin in the Marvel Cinematic Universe (MCU) media franchise, based on the Marvel Comics supervillain of the same name. He is depicted as an alien warlord from the doomed planet Titan with a universe-spanning agenda to wipe out half of all life to stabilize overpopulation and prevent what he views as life's inevitable extinction. To do this, he sets out to obtain the six Infinity Stones, cosmic gems with the power to achieve his goal. With the help of his adopted children, Thanos fights against the Avengers, the Guardians of the Galaxy, and their allies, in the Infinity War, succeeds in assembling the Stones, and disintegrates half of all life in the universe in an event that is known as the Blip. After escaping to the Garden and destroying the Stones, he is eventually killed by Thor. Five years later, an alternate version of Thanos from 2014 time travels to 2023 to battle the Avengers once again, but is killed by Tony Stark.

Josh James Brolin is an American actor. A son of actor James Brolin, he gained fame in his youth for his role in the adventure film The Goonies (1985). After years of decline, Brolin had a resurgence with his starring role in the crime film No Country for Old Men (2007). Brolin received a nomination for the Academy Award for Best Supporting Actor for portraying Dan White in the biopic Milk (2008).