Turns out, the Pillowfight Fairy's favorite theologian also happens to be her favorite inventor. She thought the Transmogrifier was a great idea. However, since she didn't have cardboard boxes, she had to make due with what she does have: white typing paper, tape, and crayons.
Just so you know, she did in fact have to ask Mommy how to spell the word "Transmogrifier."
Apparently it works, too. Both of the girls were using it today. One of them had transmogrified into a cat, and the other into a mouse; whereupon they chased each other all through the house. (At this point Mommy told them to calm down a bit, and then they turned back to normal.)
So after I came home and saw her handiwork, the Fairy explained to me her new strategy for keeping her younger sister from playing with her stuff: she would first transmogrify into a bee, then sting her sister; then she would transmogrify back, and say something bossy like "That's for doing what you shouldn't have."
I didn't mention it at the time, but maybe I should have: not even transmogrifying into another animal would save her from the wrath of her parents' discipline if she tried such a thing.
Maybe it still has a few kinks to work out. ;-)
(P.S. I just discovered my spell checker doesn't like the word transmogrifier! Who programmed this thing?)