The term "Molosser" refers to a group of large, powerful dog breeds known for their muscular build and strong, protective instincts. These dogs typically have a broad head, short muzzle, and a sturdy body. Breeds classified as Molossers include the Mastiff, Rottweiler, and Bullmastiff, among others. They are often used as guard dogs due to their loyalty and protective nature. Molosser dogs have a long history, dating back to ancient civilizations such as the Macedonians and Romans, who valued them for their strength and ability to protect livestock. Today, they are popular as family pets and working dogs, requiring proper training and socialization to thrive in a home environment.