out cat has always had an unhealthy fascination with stringy things, and with thin plastic, like plastic bags and cellophane. come christmas, he used to think that the tinsel was placed on the tree for his amusement and snackage. every so often, he would experience the "tinsel butt" effect, with us chasing him around to catch him and his decorated behind--sometimes with a cat "decoration" hanging on the end of it. (we used to call him TB--then i quit putting tinsel on the tree. whew!)
advice, though--catch the beast, and snip it off if they have string/tinsel butt. if it is pulled out, it can lacerate their gut, and possibly kill them from infection. of course, it means having to watch them for a day or two--but we all know that tinsel is pretty, and vigilance is just a means to an "end"...