Chaga, I think. Black on the outside and hard and orange on the inside. (it was growing on a yellow buckeye tree). According to what I read, I guess I am supposed to make a coffee or tea or something with it...but based upon it's un-appetizing appearance, I might leave it stuck there on the tree.
Here's a follow up of those reishi (ganoderma tusgae) knobs that I posted a few weeks ago. They are still semi-soft and so I picked one and sliced it up and put it in a half-pint of everclear 151...for medicinal purposes.