The Mastiff, also called the English Mastiff, is a large breed of dog.[1] They have a rectangular body, thick muscles and a massive head with a wrinkled forehead.[1] They stand from 27.5 inches (70 cm) to 30 inches (76 cm) at the shoulder and typically weigh between 120 pounds (54 kg) and 230 pounds (100 kg).[2] The Mastiff is one of the largest breeds of dogs[3] who can outweigh many full-grown men.[1] They can be gentle with family members but are also excellent guard dogs.[4]