My sister's cat is a freaky, friendly feline. Roo (named for the Pooh character, as you probably guessed) has an unquenchable thirst for human scalp... as I discovered when I stretched out on the floor in front of the fire.
Cat tongues are really rough. It was ticklish at first, then uncomfortable, and in the end I am sure she widened my bald spot by an inch or so.
EDIT: I uploaded a much better scan...