Gremlin. It sounds mythological, like “gargoyle” or “griffin,” but it’s not. The Royal Naval Air Service created “gremlin” as recently as WWI, and jokingly used it to refer to little creatures that could cause mechanical problems in aircraft. Roald Dahl popularized the phrase in his book, The Gremlins: A Royal Airforce Story. Thank goodness he did — otherwise the masterpiece Gremlins movies might never have come to be.