Chris Hemsworth went to great lengths to transform himself in Avengers: Endgame -- complete with a super sad soundtrack!

In the film (spoiler alert!), Hemsworth's Thor is shown to have grown overweight and despondent in the years following Thanos' defeat. He lives as a recluse in "New Asgard," consoling himself and nursing his growing beer belly with alcohol and video games, until Bruce Banner travels to recruit him to try and save the half of the world's population who got "snapped."

While fan reactions to "Fat Thor" were mixed, Hemsworth clearly had a blast portraying the new version of his usually-jovial God of Thunder, and on Wednesday's Tonight Show With Jimmy Fallon, he shared a never-before-seen clip of himself in costume on the Endgame set.

"I didn't even know if I was ever gonna shower, right? 'Cause it was like, in the trailers, in between a few takes... I method-acted the whole [thing]," Hemsworth said as he introduced the clip of him singing and playing the guitar. "What else would he be into but 'Hurt' by Johnny Cash? The saddest song in the world."

.@ChrisHemsworth debuts a never-before-seen video from the set of #AvengersEndgamepic.twitter.com/3UTQN0ilJl

Though the Aussie actor deems himself "a terrible singer and a terrible guitarist," he carries the tune just fine, and it is quite a thing to see Fat Thor lamenting all he's lost via Cash's cover of the morbid and melancholy Nine Inch Nails track.

"What have I become, my sweetest friend?" Hemsworth sings in the clip. "Everyone I know goes away, in the end."

Last month, the actor opened up to Variety about portraying a new version of the Marvel character, whom he's been playing since 2011's titular origin story -- and why he fought against the idea of Thor returning to form midway through the epic Avengers finale.

"I like that anything goes," he said. "You're not locked into expectations. I enjoyed that version of Thor. It was so different than any other way I played the character. And then it took on a life of its own."

As for whether or not he'll ever embody the Asgardian prince on screen again, Hemsworth is leaving the door open.

"I'd still love to do more, to be honest," he said. "And I don't know what the plan is. I feel like we've opened up such a different character. I feel more energized for the possibility of where it could go. But I'll use that in other places and other characters if it's the end here."

See more from the actor, who next reteams with Thor: Ragnarok co-star Tessa Thompson in Men in Black: International, out June 14, in the video below.

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