MEET Kobe, son to giant pitbull, Hulk, who is going to be the next ultimate protection dog. Earlier in the year the biggest pitbull in the world - who weighs a whopping 12 stone - fathered eight puppies that could collectively command $500,000 (£320,000) if they complete owner's Marlon Grennan’s training school to become elite protection dogs. Marlon, 28, is currently training the next big star of Dark Dynasty K9s with eight-month-old puppy Kobe. At the beginning of Kobe’s training the powerful