boxer: a breed of stocky medium-sized short-haired dog with a brindled coat and square-jawed muzzle developed in Germany
working dog: any of several breeds of usually large powerful dogs bred to work as draft animals and guard and guide dogs
b cell: a lymphocyte derived from bone marrow that provides humoral immunity; it recognizes free antigen molecules in solution and matures into plasma cells that secrete immunoglobulin (antibodies) that inactivate the antigens