Thaumatrope (English pronunciation) is a Victorian-age optical toy, one of several early animation inventions (others include the zoetrope, the magic lantern, the phenakistoscope, the praxinoscope, and the flip book).
I've been fiddling with thaumatropes for a few days at the museum where I work as an educator. We have a family night coming up this week and I've been getting things ready to take for demonstrations and activities (so much cool stuff). I made a very special thaumatrope for people to color and take home. It features the museum's own resident celebrity iguana, Renegade! You can download it here, along with directions, and make your own thaumatrope: renegade thaumatrope
This was really fun to make, but also a little tough to conceptualize - all the different orientations made the design a little confusing to me, but I think overall it worked out all right.