Strange group, unless the frog turns into a prince when a pretty girl in royal garb kisses him. Even so, I can't think of a more boring animal than a frog, so he's out. Fairy? What kind of fairy? (Dare I ask?) Let's leave that unknown out too. That leaves unicorn. I kind of like it. I'm more intrigued by a pegasus, but unicorn is still an interesting mystical creature.
Unicorn for me, please.