H.S.
I don't know how you could make it, but it's just a gussied up aquadoodle. I got one @ Target on clearance last year, so you might be able to find one on sale - or even a used one on craigslist or freecycle. If you can get a free one or a really cheap one, even if it's not in good shape, you might be able to use that to dissect and try to figure out how to make one.