MCU: 10 Fascinating Facts Behind The Avengers (2012)
1. Cap's Invisible Beard
Famously, the shawarma scene at the end of the film was added at the last minute - after the press screenings in fact and after the cast had all broken up for other projects.
In that scene, we see all of the Avengers sitting around exhausted and eating shawarma, but Captain America is conspicuously not eating. That's because he can't thanks to a prosthetic chin designed to hide the beard he was growing for Snowpiercer.
Instead of going the DCEU route and CGIing his face, they covered his lower jaw with rubber and gave him a blonde wig. He covered his face because the prosthetic wasn't exactly very convincing and he looked like there was something massively wrong with his face.
Incidentally, in the wake of the movie's release shawarma sales in Los Angeles, St. Louis, and Boston all went through the roof.