n: The gnarliest, nappiest, most tangled thicket of pubic hair known to mankind.
Many different species of animals may inhabit the possum's haystack, because of the multiple ecosystems grown over time.
Nobody really knows how people become inflicted with the possum's haystack, however, experts do believe that it could possibly obtained from little to no maintenance to the "under rug" for many, many years. The condition, however, is fatal.
Reginald M. Nooker was the most famous case of possum's haystack. He did not trim his pubic hair for 39 years. His hair follicles were so overactive that they did not grow long, but thick, and tough, and they curved back and around in every possible direction. He broke many chainsaws simply trying to find his penis.