The following picture is not animated. Your eyes are making it move.
To test this, look at theblack centre of each circle and it will stop moving.
But move your eyes to the next centre and the previous one will start moving again.
The picture is called "Rotating snakes" andwas created by A. Kitaoka. You can find more of his artwork here.
(Click on photo to enlarge)
Some ASCII Drawings: