Whoopee cushion
Whoopee cushion
Credit: Grombo

A whoopee cushion, also known as a poo-poo cushion and Razzberry Cushion, is a practical joke device that produces a noise resembling a raspberry or human flatulence. It is made from two sheets of rubber that are glued together at the edges. There is a small opening with a flap at one end for air to enter and leave the cushion. To use it, one must first inflate it with air and then place it on a chair. An unsuspecting victim sits on the whoopee cushion, forcing the air out of the opening, which causes the flap to vibrate and produce its distinctive sound.