I posted an image of a black squirrel recently and was told by a couple of hoggers that they had never seen a black squirrel before.
As it turns out they are very rare save in East Texas. I would say that every fourth squirrel I see is a the Eastern Texas Black Squirrel...the black squirrel is a melanistic sub group of the Eastern Grey Squirrel and is reportedly seen across only 1 in 10,000 times. Not so in east Texas as you can read in the text of this link: