Once you see a Neapolitan Mastiff you're unlikely to forget it. They're massive dogs, with folds of skin, pendulous dewlaps and a heavily wrinkled face. Bred as a defender and guard dog, he is loyal to his family and a serious deterrent to others. Because of his size and temperament, this may not be the right breed for families with small children or for first-time pet owners. It's important to teach your Neapolitan Mastiff puppy basic obedience early while he's still a manageable 40-60 pounds. He'll grow up quickly and will do best with owners who are mindful of the specific needs of the breed.