A body type of someone that gains muscle easily, is bursting with muscles, loses fat easy, has a V shaped back, thick skin, large penis and a tough jaw. Can throw around ectomorphs like rag dolls.
Typically a very sexy body type. Women that don't want a vegetarian-anorexic-looking ectomorph like these types.
Famous mesomorphs, Vin Diesel, Arnold Schwarzanegger, Bruce Willis, LL Cool J and Optimus Prime