This guy is having A LOT of fun!

From Wiki: Silly Putty (also marketed by other companies as Thinking Putty, Bouncing Putty, Tricky Putty and Potty Putty), is the Crayola-owned trademark name for a class of silicone polymers. It is marketed today as a toy for children, but was originally created by accident during research into potential rubber substitutes for use by the United States in World War II. The company's manufacturer is based in Easton, Pennsylvania.