My pet bearded dragon (Viper(Her Name)) tail is black from halfway down and I'm quite worried from what I've read and it seems to be part of her not shedding skin. I'll supply some pictures but answer quickly it's been like this for a while. I also keep her warm when she's out of her cage but it seems to be striped aswell(tail)
http://imgur.com/ijD4FDx
http://imgur.com/c3izCDd
http://imgur.com/e6QMTDA
http://imgur.com/ijD4FDx
http://imgur.com/c3izCDd
http://imgur.com/e6QMTDA