Courtesy of Japanese prankster Faru Arufa (which you should not Google unless you want to see thing you cannot unsee), comes this invention that allows you to launch a fart directly into the face of your friend (or former friend, after this).
First you take a normal, unassuming box.
Cut a hole.
And test your air cannon.
Then, well, you can see (unfortunately).
A diagram for how this insanity should work.
Unless your victim gets a clue as to what’s happening.