My son is petrified of his new puppy what should I do?

I bought my son a german shepherd puppy for Xmas. He has named him rufus. I had some problems with rufus in the days leading up to Xmas but they were nothing. Since Xmas day rufus has scratched my son twice - drawing blood the second time and looked as though he was going to bite me. I think I am all out of options. My only hope is a vet friend who I'm seeing later and I fear we are going to have to make that awfullest of decisions.