What is "beerhead"

Usage examples of "beerhead".

He takes me outside the gates of the prison camp and we walk along a road about a mile when we come to a small house set back from the road in a grove of trees and Schultz stops in front of this house and speaks to me as follows: "Lace," he says, "in the course of your playing with the captain kindly do not refer to our people as krauts, pretzels, beerheads, Hei-nies, Boches, sausages, wienies or by the titles of any other members of the vegetable or animal kingdom, and do not tell him what you Americans are going to do to us.