In case you haven’t seen it before, here’s a sweet and fun optical illusion: a paper dragon that seems to always turn its head to look at you.
Curiously, this illusion works much better on video than in reality. In reality, you need to close one of your eyes to fool your depth perception.
This originated as a conference give-away made by Jerry Andrus in 1998. Fans meet biennially to celebrate the life and work of Martin Gardner, and an American popular mathematics and popular science writer. Each participant must bring 400 copies of something they made, and everybody leaves with one copy of each item. Fun!
Want to make one yourself? Here are three versions, ready to print, cut, and glue:
Oh, and “Percy”? I made one of these to show my kids, and Daniel named it Percy. It sits on my desk and watches me carefully.
I dedicate this post to my grandmother Lizzi who would have been 97 today. She would have enjoyed this illusion.