The history of carving miniature bas relief sculptures into coins stretches back to the 18th century if not earlier. It was greatly popularized in the early 20th century with the introduction of the Buffalo nickel. This particular coin was minted using soft metal and was imprinted with the portrait of an indian with bold features, making it easier to deface and transform into the portraits of other people, animals, or even scenery. it is known as "Hobo Coins". Those skull ones are mad!!