Have you ever heard anybody use the term mule coin?
A mule coin is a coin that has an obverse (heads side) and reverse (tails side) design that wouldn’t ordinarily go together on the same coin.
Mule coins have long attracted the interests of coin collectors. Such coins produced by accident are high on the want lists of many error coin collectors!
One of the most popular mule coins is a dollar-size coin showing the obverse of the Washington state quarter and the reverse of a Sacagawea dollar. It had sold for over $40,000 when first found and authenticated!