"My ___ Grew A Beard" is a lesser meme that is typically circulated around followers of heavy metal culture. More specifically, Viking Metal, and most notably, the Swedish Melodic Death Metal band known as Amon Amarth. It is a joke that is typically told in the comments section of YouTube videos of their songs.

Amon Amarth's songs are typically about Vikings, which are often depicted as overly manly, with large beards. The burly, heavily bearded appearance of the band's lead vocalist, Johan Hegg, further pushes this idea. The joke is that the band's songs are so manly, and carry such Viking nature, that the sheer sound of them can bring pure unfiltered manliness to all who are within the audible range of it. The joke is often told in a manner similar to this: "I turned on the song, and looked away from my cat. When I looked back, my cat grew a beard."

It is unknown exactly who posted the first comment regarding this, or what the original comment even is, but it has been a joke for several years by the band's fans.