it's a thaumatrope. when i mention it by name no one seems to know what it is but once i explain that it's a toy that usually has a picture of a bird on one side and a cage on the other people usually understand. when you spin it the bird appears to be in the cage.
here is my thaumatrope for my friend abe:
i couldn't get a picture of it in action, but rest assured that it is awesome because he is BACK IN THE USAbe!