... it so funny?a whoopee cushion, also known as a poo-poo cushion and Razzberry Cushion, is a practical joke device ... one end for air to enter and leave the cushion.To use it, one must first inflate it with ... chair, an unsuspecting victim will sit on the whoopee cushion, forcing the air out of the opening, which causes ... on it, the air in the cushion will escape.put a whoopee cushion in someone's chair as a ...