Warning: This article contains potential spoilers for Guardians of the Galaxy and other Marvel films.
Thanos isn't known for playing well with others, so it's a bit surprising to hear of him popping up in so many movies. His Infinity Gauntlet appeared on Asgard in 2011's Thor, long before fans got their first glance of the Mad Titan at the very end of 2012's The Avengers. With the recently announced casting of James Brolin as Thanos in Guardians of the Galaxy, speculation about the extent of his role in the August-premiering film, and beyond, has run rampant.
According to Vulture, Thanos appears throughout Guardians of the Galaxy, primarily as a hologram, but also shares a scene with Lee Pace's Ronan the Accuser and Karen Gillan's Nebula. That matches what director James Gunn said last year about the working relationship between Thanos and Ronan. “Thanos is a character in our movie,” he said. “He works with Ronan. In my movie Ronan works for Thanos, and Ronan is the main bad guy in our film.”
Whenever Thanos does step out of the shadows -- likely in the third Avengers film -- you can bet he's on the hunt for the Infinity Gems, powerful sentient stones representing Mind, Reality, Time, Space, Soul and Power. Benicio del Toro's Collector popped up at the end of Thor: The Dark World to snag Aether, noting, "One down, five to go." It wouldn't be ridiculous to guess that Ronan and Nebula are on the hunt for more of the gems in Guardians of the Galaxy, meaning Thanos' specter hangs over the film .
Opening Aug. 1, Guardians of the Galaxy also stars Chris Pratt, Zoe Saldana, Bradley Cooper, Vin Diesel, Dave Bautista, Djimon Hounsou, Michael Rooker, Benicio Del Toro, Glenn Close and John C. Reilly