Charlie Chaplin Mask Illusion
A mask of Charlie Chaplin?
Okk, now carefully watch the video of 'Charlie Chaplin Mask rotates around on a stick' below :
No matter how hard you try, the hollow and concave rear of the mask eventually becomes a convex golden face that spins counterclockwise.
BTW, don't you think it is one of the best ever example of spinning optical illusion.