Sending the newbie off to get a bowl of co2. Usually the other store is set up to end up giving them a bowl just covered. If no basement tell the newbee when asked "where is x" reply "its in the basement."
Make a roux and call it butterscotch pudding. Someone always tries it. Wrapped a coworkers jeep, inside and out with plastic wrap. put confetti in a friends car vents, so when they turn on the car it blows out on them.