I have a Great Dane- Pit Bull Mix and I need a name for him?

Okay, i just went and picked up a almost solid blue Pit Bull Great dane mix, I got the stockier, bigger block headed of the dogs in stead of the longer blue merle colored one. Anyway, I want an intimidating name for the dog, something that will suit a tall, bulky dog like he is going to be. I wanted to name him either Rhino or Magnus, but please put your input in. Thanks.