Yup, a travel pillow. And we had a grand old time, and it didn't take up much time at all. (Some of our answers included a toilet seat, giant phone, nose ring, every facial/body hair you can imagine, an elephant trunk, a giant's bangle, football shoulder pads, Geordi's viser, bunny ears, the front half of a puppy, etc...)
This is a quick, fun game to play with kids, too--and it encourages creativity! Grab a weirdly-shaped-something in your own house and play, with your spouse or whole family. And enjoy the giggles, because there will be plenty! :)