The material below is Open Game Content from a 3PP Source
MERCHANT’S MOLD (CR 1)
Named for the profession that first discovered it, this gray, thick growth is sometimes found in sacks of grains or coins that have traveled great distances without being opened.
Merchant’s mold is usually confined to the bags it is found in though, when bags are left undisturbed for many years, patches of up to 100-ft. in diameter can develop. If disturbed, either prodded or walked on, merchant’s mold belches forth a cloud of disease-carrying spores. All within 15 feet of the mold must make a DC 15 Fortitude save or be subjected to filth fever (see the SRD).
Fire destroys merchant’s mold.