During the song Walter sees himself in human form, while Gary sees a Muppet version of himself. The four complete the song together.
Songwriter Bret McKenzie discussed the process at length in a New York Times blog interview:
“I was channeling power ballads — Harry Nilsson, “Without You” — [singing] “I can’t liiive, if living is without yoooou.” And Eric Carmen, “All by Myself” — [singing] ‘I don’t want to live, alllll by myself.’ Those are two of my favorites. I knew this had to be an incredibly dramatic song. It’s one of those, the more serious the song is, the funnier it would be. I just wanted to make it as epic and dramatic as possible. That’s why the chorus is just these relentless long notes at the top of Jason Segel’s range. There’s something about guys singing at the top of their range, it’s really emotionally desperate.”
In 2012, Bret McKenzie was honored with an Academy Award for "Best Original Song" (albeit with only one other nominee in the category). "Man or Muppet" marked the first Oscar win for any Muppet production.
Jim James of My Morning Jacket had written a demo of the song, but it was deemed "incredibly mellow" and was rejected by the producers.
To promote the release of the film's soundtrack, Walt Disney Records released a music video of the song intercut with clips and dialogue from the film. In conjunction with the release of Muppets Most Wanted, Vevo release the music video to YouTube with commentary by Constantine.
The music video version was released on a limited edition album, The Tributes Collection.