Have you seen that old game where two images on separate discs are spun to make it look like they are together? It's called a Thaumatrope.
A thaumatrope is a toy that was popular in the 19th century. A disk with a picture on each side is attached to two pieces of string. When the strings are twirled quickly between the fingers the two pictures appear to blend into one due to the persistence of vision. (wikipedia)Now you can make your own Thaumatrope (my teens just call them spinners) and use it to catch Pokemon. To make this toy you will need the print out this PDF or Publisher file, scissors, a single hole punch, string or yarn, a way to color your picture like crayons, colored pencils or markers and glue or tape.
Catch your Pokémon by coloring and pasting the circles together so that each image is upright no matter what side you look at. Next you need to punch two holes across the diameter of the circle and attach strings from each side. Spin the strings to see the optical illusion.