I had a black furry patch on my tongue several years ago, and it scared me. I went to the ENT doctor, and he said it was from taking the antibiotics I'd been taking for a long time. I got off them and the black furry patch went away in a couple days. This patch was about the circumferance of a tablespoon, maybe a little smaller. Very scary.
mole maybe, my mom has one on her eye ball.