Halloween themed optical illusion based on the "Jastro Illusion" (also often called the "Boomerang Illusion"). The oldest reference to this illusion can be found in The World of Wonders, an 1873 book about curiosities of nature, science and art.
It is recommended to print these on cardstock. When cut out and held side by side, one of these two shapes will appear larger. But when the shapes are switched, the other now appears larger. If printed front and back (as recommended) the back of one of the shapes will contain an arrow and the words "SEE! THEY'RE THE SAME" so that one can be flipped over during the trick to show that both shapes are the same size.
*PLEASE NOTE: This product contains a Christian message.