24. Bullmastiff

As the name implies, the bullmastiff is a cross between a bulldog and a mastiff. This hound has the potential to reach a height of 27 inches from shoulder to ground and a maximum weight of 100 pounds. In the nineteenth century, these dogs were deployed to discourage poachers. These dogs have been educated to be defenders, but they are still able to form close bonds with their owners. They did this by developing and displaying aggressive and authoritative exteriors. The breed, however, could revert to its original state and become dangerous to even its own families if it is not properly socialized or trained.