Growning up I always had Wolf/Malamute Hybrids. But I have always wanted a German Shepard. I reccently purchased one, without papers. I chose him from a pup after looking over his beautiful parents. His Father was pure black and mother bi colored black and tan. He came out pure black, but has some odd features to him, so I am concerned maybe somewhere down the line he is not "pure" (even though most dogs aren't pure breed anymore) He has a spec of white on his chest, which I understand are normal, but what gets me is this white patch on his tail. It is like a thick white undercoat under his black, that is only on the top part of his tail in a perfect spot. It is very coarse and turns into a weird puff ball on his beautiful sleek tail when he is angry or excited. The fur on the tip of his tail curls, like in a weird spiral off the tip. Overall I know he is a beautiful german shepard, I am just curious if these odd things are normal? Or if he really does have some odd mix in him.