Too funny about the growl. I've heard the grey growl and it's scary!
Is he eating all the food you're feeding twice a day?
Yea, but greys are also sometime apologetic, like my grey will bite out of playing. I get my hands to close playing with his toy with him and he misses you and gets my hand....I say ouch!! Hey!! He responds back...opps! Then runs his head on my hand as if saying sorry.