With no credited source, performer or original scene attached to this clip, the grrrr growl has spread purely as a reusable reaction sound on soundboards and in short edits. Its appeal is how readable it is without context, a long guttural rumble that anyone can map onto anger, jealousy, hunger or mock menace in a couple of seconds. Creators keep reusing it because it works muted as a caption and loud as a punchline, and it fits pets, characters and people equally well.