My lovely girl is one next week and is brilliant most of the time. However, for about the last month or two, if she comes and sits with me and we have a cuddle or even if she is just on my lap she will almost every time start biting my arm, gets harder and harder and then she starts clawing me and being really vicious. I will tell her off firmly and put her down but then she literally throws herself at me and gets really nasty....my arm is covered in blooming scratches and she does it to my son as well.
Any ideas why she has suddenly started doing this. DH reckons she needs her first kill to work her aggression out on but it's not my fault so far she has only managed to eat a crane fly 
It is a phase.....I have had cats for years and never had one do this. In other ways she is a gorgeous girl with a great personality and she loves company so wherever we are, she is always near. She has a scratch post, lots of love and attention and goes out whenever she wants so not really sure why she does it.