I don't want you to hurt your frog that's for sure. I've had to pull a strand of moss out of one of my pacmans back when I used moss. Lukily it was only in her about an inch. No harm was done, but with a strand of hair there is no telling how far it could be. This is very uncomfertable for the frog. You may have to see a vet and get some amphibian laxatives to make him expell the hair. Or the vet may try to pull and see if can be extracted with out harming your frog. This is touchy. You can still try just to see if it moves a little, but the moment you feel any resistance hou must stop. If you would rather a vet see him it may be best.