This shows how it works and how to make one.
This is optical illusion that you can print out cut out and tape together. Can be found at this link http://www.curiouser.co.uk/illusions/dragon/dragon.jp...
Fun modular origami butterfly ball model made from 12 units. After assembled, toss it in the air and give it a whack. The model will burst apart and butterflies will fall to the floor.