Have you ever heard of the Boxer dog? They're medium sized, short haired dogs that originated in Germany. 
I think I've seen them before. Do they have squarish, boxy-type heads?
Yes! They are a "brachycephalic" breed, which means they have a broad, short skull, square muzzle, and usually an underbite. 
I do know those dogs! I had no idea they came from Germany.
They were actually bred from the Old English Bulldog and another breed, the Bullenbeisser, which is now extinct due to the crossbreeding.