A dorf popper is someone who enjoys farting in the bathtub and when the bubbles get to the top of the water, they pop them with there teeth. Not only is this a term for someone who actually does the act of popping a dorf...but it is also used as a dirogatory term. One final note: "dorf popper" is most commonly used in Germany
That guy is such a dorf popper.
A fart sniffer who has names for durations of his/her farts and other people, also can tell what foods made them.
"My that's a fruity vintage, you recently had apples & cashews!" exclaimed the fartmeister.