i did two small pranks. i stuffed paper in people's shoes, and froze some pop in a cup then poured not frozen pop in the same cup and served it so when they drank it they got fresh pop then hit ice! funny but small. a good idea would be to put food coloring in a bowl and then pour cereal and give it to the person who you're serving it to along with some milk then let them pour it so when they pour it, it will turn into a crazy color.