The best way to describe is it looks like some charcoal or dirt rubbed off on a few scales on his back, and now it's a bit on on his head too. It's very dark and on a few scales here and there, but when I bathe him, it won't come off. I have raised him, and never had any problems with his health before. He is about 1 1/2 now. What could this be? Is it some kind of fungus? I live in Colorado, so it's very dry here. He eats mealworms and collard greens. His temps are all correct. Tile floors, with a sandbox on one end of the viv.