Take this dragon, for example. Stand back a couple of meters away and stare at it and it stares back at you. With your eyes still on the dragon, move to your left, then to your right. The dragon does not lose its sight on you! There's no special mechanism in it, all you need are cardboard paper, a colored printer, a pair of scissors, and some paste or glue.
Look at my pet dragon at the office... staring at me. Perhaps in bewilderment due to my desk clutter.
The first step is to get the pattern. This is free to download from any of the following sites:
Great Things on the web
Pinwire - video of the dragon included
Then, simply print the pattern onto your cardboard paper, cut it out, then build the structure by following the mountain and valley-fold instructions. You should get this result:
The illusion is best experienced when the dragon is illuminated from behind and below it so the head gets lighted up. Try it! Simple fun.
The Gathering for Gardner is a non-profit organization whose goal is to promote the lucid exposition and discussion of new ideas in recreational mathematics, magic, puzzles, and philosophy. This dragon was made to commemmorate the third conference.