From article:
“So I woke up with something that’s literally Black Hairy Tongue. People, including my doctor, seem to think it’s no big deal, and will go away soon, but it certainly is gross,” Powell tweeted on October 25.
The Mayo Clinic’s website describes black hairy tongue as a “buildup of dead skin cells” that accumulate on the tongue, explaining that while it can look alarming, “typically it doesn’t cause any health problems, and it’s usually painless.”
https://gizmodo.com/julie-powell-black-hairy-tongue-last-tweet-death-49-1849730851
Have seen it many times. Usually from (strong/long-term) antibiotics...fungal overgrowth...imbalance. Had it as a kid when taking clindamycin for zits. Diflucan or nystatin knocks it out.
Not a big deal.
Although...poor immune system not taking care of fungi can contribute. Usually it's candida, tho.