I know fellow Spain compadres, that have practice this, it is weir listening to children singing the poop log song, because in some Spanish language the word "cagar" is a vulgar but they use the word in the song, the song talks about a log that shits candy, but el caganero "the shiter" is a guy that poops in a hidden corner in the nativity scene, well what i heard from it, when Jesus was born, there was somebody emptying their bowls at the moment when Jesus was conceived. the whole point of the guy pooping, is that you have to look for him, like the were is waldo books, so next time you see a Nativity scene, please look for the pooper in the hidden corner, it will bring good luck this year!!