Thank you all so much for the info. I want to make one like yours jazzcat, but I did not know what to put around the outer edge, to make it stick up and look kind of like their kitty condom, only much bigger/fluffier. All you used was cotton stuffing, like in a bag from walmart?
I also like the comforter idea, because I want something large they can all share in the winter. These are great ideas! Thank you all very much