This sound is best understood as a user-made sound effect rather than a clip from a specific film, show, or meme character. The 8D label refers to stereo panning and spatial processing that makes the knocking seem to move around the listener, especially on headphones. Sounds like this spread widely on short-form video apps, prank compilations, and soundboards because they create an immediate physical reaction. It remains useful because a simple door knock is familiar, and the moving mix makes that familiar sound unexpectedly convincing.