I actually did something similar to that this year. My sister wanted a large frying pan for Christmas this year, and my parents bought her one. I wrapped it nicely in a large box, with ribbons and bows. You can't tell what it is. I even added sound dampening material.
...And then on the present I bought her, a Dr. Who blanket, I wrapped it in a large box, and stuck a wooden dowel out the side shaped like a pan handle. Because even Christmas needs some nefarious plotting. >_> If this is what you would call a prank gift, then I am 100% for it.

As for penguins I would put them up. Seems like people are using penguins for Christmas decorations this year, and while I'm not wholly OK with that, I am wholly OK with penguins. So in the end, it balances out. For year round usage, totally. I'd love that. XD
Plus, with a bit of paint and glue, you could make them into the Madagascar Penguins, and have them peeking out from behind trees, or climbing your house.