The name comes via the title of one of the extras featured in the movie's home-viewing versions. The mini-documentary, titled Bro Thor, explores Thor's Big Lebowski transformation after he faced off with Thanos and misaimed his axe Stormbreaker to disastrous consequences.
"His appearance has changed but his heroism remains! Go behind the scenes to see how Bro Thor was created," the featurette's description reads.
Thor's radical new belly sparked criticism over fat shaming and the mean-spirited jokes Rocket slings his way. Others applauded the decision to have Thor stay in his larger shape for the final fight scene, instead of reverting to his earlier Norse god self.
You can check out the featurette and many other extra features on digital as of July 30, and Blu-ray on Aug. 13.