The Boxer is a medium to large, short-haired breed of dog, developed in Germany. The Boxer was bred from the Old English Bulldog and the now extinct Bullenbeisser which became extinct by crossbreeding rather than by a decadence of the breed. The Boxer is part of the Molosser group. This group is a category of solidly built, large dog breeds that all descend from the same common ancestor, the large shepherd dog known as a Molossus. This group is a category of solidly built, large dog breeds that all descend from the same common ancestor, the large shepherd dog known as a Molossus. The Boxer is a member of the Working Group. The name of the breed could also be simply due to the names of the very first known specimens of the breed (Lechner's Box, for instance). Boxers need plenty of exercise which means their diet should be high in quality calories.