I would buy a canvas paint tarp, they're pretty inexpensive at Home Depot, etc... wash and dry it they soften up nicely, and they're a nice neutral color, like oatmeal. I did that for curtains in my living room with some embelishments, people loved them. With a zipper, or velcro closure... for that matter, you could even forget the hardware, and make it like a big pillow sham, you know the two sides overlap in the back?.. if he tears it up, so what, you could make another. You can buy an insert for it, or foam, or stuff it with straw.