Where I work we have to collect samples of our product for testing in the lab. Some of the samples are collected in specimen cups, which presents the perfect opportunity for some pranks. This one is similar to the "stool sample" prank. All you need is a specimen cup and two sailor minifigures. Just glue the minifigures in the cup, write "seamen sample" on the label and leave it in the fridge for the lab to discover. Then sit back and wait for the hilarity.