Yikes !!! Cobra Eggs. So what do you expect ? The envelope warns you. But the person who sees this cannot resist opening it to see what is inside. And he's or she is in for a shock ! A novelty item that has been popular for years in many forms, (Viper Eggs, Shocking Letter etc.) this is a buzzing device in an envelope, that goes into action when the envelope is opened. Comes at a very low affordable price, and you can buy them by the dozen as a novel "giveaway".