Hammer-Heads are creatures of a rather small race who inhabit the magical Land of Oz. They are an unusual and bizarre species who live strictly on the top of a small and rocky mountain (often referred to as a hill), in Oz's southern quadrant known as the Quadling Country. They first originally appeared briefly towards the end of L. Frank Baum's first Oz book titled The Wonderful Wizard of Oz, published in 1900. They are placed as another rough obstacle which Dorothy Gale, Toto and their three Oz companions, the Scarecrow, Tin Woodman, and Cowardly Lion must encounter during their long quest to get the girl and her dog back home to Kansas again. When they meet these peculiar creatures, they are not happy to see the traveling group of friends as they approach them to climb over their hill to pass through to the other side.