https://www.wikihow.com/Make-a-Paper-Popper
PAPER POPPERS!!!
A paper popper is perfect for scaring or pranking your siblings and friends. By folding a piece of paper correctly, you can create air pockets that will make a loud popping sound if you snap the paper down using the right technique. All you need is one piece of paper and some wrist power, and soon you’ll have a popper of your very own!