If you don't know what is a Mondegreen, go here. For more detail go here, and if you can read that without laughing you're not human. But, this, this video, it takes it to a whole new level.
Full disclosure: I'd been singing "When I go to town to spend my pay, with flat car riders and cross tie walkers ..." for nearly forty years when I found out what Creedence Clearwater really sang. At least I din't enter any contest.