Richard, Chuck gets like that sometimes. You can be petting him all nice and WHAM! You're bleeding and he is giving you the stink eye. I call that wrong button syndrom. If I just knew where that wrong button was..LOL
One night I was having fun blowing in his face to see what he would do. Mind you not hard just softly. The next thing I know, he is wrapped around my head and biting my scalp. Needless to say, I haven't done that since. Imagine a 20 pound cat wrapped around your head!