WARNING: This article contains spoilers for Thor: Ragnarok, in theaters now, and for Marvel Comics Planet Hulk storyline.
Fans likely already know that Thor: Ragnarok borrows heavily from Marvel Comics' "Planet Hulk," but just how much is actually taken from that fan-favorite 2006-2007 storyline?
To understand how director Taika Waititi's sequel pays homage to those comics, we'll need to briefly revisit the storyline by writer Greg Pak and artists Carlo Pagulayan and Aaron Lopresti: Before the events of Marvel Comics' Civil War, a group of superheroes called the Illuminati (Doctor Strange, Tony Stark, Professor Charles Xavier, Namor, Reed Richards and Black Bolt) banished Hulk from Earth after he nearly destroyed Las Vegas, believing him too dangerous to remain free. He's tricked onto a space shuttle that's supposed to rocket him to a peaceful world, where he would be left alone, but the vessel went off course, traveled through a wormhole and crashed on the savage planet Sakaar.
Fixed with an obedience disk, Hulk is enslaved and thrust into gladiatorial combat for the amusement of Sakaar's ruler, the Red King. He eventually becomes the strongest being on the planet, then the leader of an uprising and, ultimately, Sakaar's new king. It all goes wonky when the ship he crashed in explodes and kills the woman he loves. Hulk then returns to Earth to vengeance in the subsequent "World War Hulk" storyline, but we won't get into that here.
Throughout "Planet Hulk," the Green Goliath gains some powerful allies called the Warbound, composed of fellow former gladiators; they're heavy hitters on par with the Hulk himself: Korg, Miek, no-name Brood, Elloe Kaifi, Lavin Skee and Hiroim. Some of those characters appear in Thor: Ragnarok, while others don't, because of changes to the storyline.
Now we can dive into where, and how, the plot of Thor: Ragnarok intersects with that of "Planet Hulk."
When we last audiences saw the Incredible Hulk (Mark Ruffalo) in the Marvel Cinematic Universe, he was alone aboard a Quinjet on stealth mode at the end of 2015's Avengers: Age of Ultron. The aircraft was later transported, with Hulk on board, to Sakaar. It's similar to how he ended up on the planet in the comics, but the filmmakers took some creative license; when Hulk explains to Thor (Chris Hemworth) what happened, he does so by pantomiming a crash with his hands. It's funny and it works.