Its not an aggressive growl... he growls all the time, its like he is talking but it is growling, when he plays, when I talk to him and he is getting pets, if anyone else ever heard him when he was playing they would think was a killer. I have never had a dog who growled so much, Babs growls when playing a bit and of course she grumbles under protest for things she does not want to do (like go to crate sometimes) but my lord Capone is a noisy boy.