The Neapolitan Mastiff is a natural guard dog and his protective instinct will kick in if he senses any threat to his home. His slobbery affection for his human family, however, makes him seem a lot less intimidating, and they are generally very calm. His large jowl means that he dribbles and drools a fair amount so it's a good idea to line his bed with washable blankets. Since being thirsty increases the problem, do place a mat under his water bowl too!