Black Hairy Tongue (aka Black Hairy Tongue)
Yes, this is a real thing and not a gross-out urban legend. It's the appearance of dark hair covering the surface of the tongue. It will look like a person lovingly cleaned the exhaust system of a decade-old 18 wheeler, with the gentle precision a mother cat applies to her own litter. This oral ashtray effect is nasty, although an attention getter. And everyone loves attention, right?
It could happen to you, too, if you're kind of a filthy person. If you'd like to give your mouth a warm fur coat for winter try these three steps: 1. Stop brushing your teeth. 2. Enjoy your coffee like Kim Kardashian enjoys her men. 3. Smoke; you're not getting any younger and it'll make you cool*.
If you follow this strict guideline your mouth may wind up with a coat that will keep it warm through the snowy months, and will block those drafty winds when opened for a make-out session.
*Coolness reports based off of 1950s studies and James Dean posters.
What causes it?
Your mouth is teeming with filth. It is a truly perfect swamp for the breeding and growth of bacteria and grime. The hairy tongue is an overgrowth of these bacteria, and sometimes yeasts that are present. Papilla, the finger-like projections from the surface of the tongue, become awash in this bacterial stew. In instances of hairy tongue the papilla often cease to shed normally, growing longer and creating more surface area for the bacteria to attach to. Thus, it grows into something that looks terrifyingly like hair.