The pictures aren't clear, but it sounds like it's some retained shed. As others have suggested, you can place a humid hide in his enclosure. After spending a bit of time in there, the shed might come off as he rubs on things.
To increase the overall humidity in his (I'm assuming glass aquarium), you can mist his enclosure, use a substrate that better retains moisture (such as coco husk), and place a damn towel over the screen top.
Good luck and enjoy your new pet!
Reply With Quote