Probably fishing line. The reason I am guessing that is because there's a fairly famous photograph that I have (but it's not available to scan) from The Wizard of Oz(1939; ya know, with a pill popping girl from Kansas and a gay lion). It's when they're about to be attacked by the Witch's guards, and in order to get the pose just right, someone rigged a piece of fishing line around the Lion's tail to pose the tail too (you can actually see it in the picture). And to that end, the same rig was also used in "If I Were The King Of The Forest".