Every once in a while some kind of unexplained phenomena hits the web in the form of a video (or many videos), and everyone goes wild trying to figure out just what in the hell it really is.

One such phenomena has reached these heights recently. In numerous videos posted from all over the world on YouTube, a very loud, very intimidating noise is heard. Listening to it you can only assume that a giant alien craft, Godzilla, King Kong, or some dinosaurs are about to come barreling into your back yard. So is it a clever viral marketing campaign, an elaborate hoax, something natural, or something else?

Continue below to check out videos from multiple locations experiencing these mysterious strange sounds and share your thoughts!