Japanese prankster Faru Arufa is a bit of an interesting individual and to be hones you shouldn’t Google him. And if you do be prepared to see things that you cannot unsee. In this case Faru Arufa created a fart canon where you can aim a fart into your target’s face.
First you take a normal, unassuming box.
Cut a hole.
Then, well, you can see (unfortunately).
A diagram for how this insanity should work.