The Neapolitan Mastiff or Italian Mastiff, () is a large, ancient dog breed. This large breed is often used as a guard dog and family protector. Despite their looks, they are a big gentle dog with family and friends. They can be trained as guard dogs to protect people or property. Neapolitan Mastiffs need a lot of daily exercise. They are directly descended from the Tibetan Mastiff, one of the oldest dog breeds.