No, it's not Ozzy. It's a Tibetan Mastiff.
The name Tibetan mastiff is a misnomer because technically it is not a true mastiff. A better name for the dog would be Tibetan mountain dog or Himalayan mountain dog. These dogs are seriously huge. An average male weighs 80 kg. They were and are still used to guard herds and flocks, tents, monasteries and palaces. They are mostly tied up to guard houses. It's Tibetan name means "dog which may be tied or door guard or home guard".