Ever since my son came home from the Apple Store with the game called Spore, our home has been a stomping ground for fantastic creatures. Spore is an easy, fun animation software that allows you to create critters-from-another-planet. They move, run, dance, have mating calls (and babies), and have their own personalities.
With some instruction, I managed to make my own Spore. I call him Aviamph, because he can swim and fly.