1911 Encyclopædia Britannica/Mascot

MASCOT (Fr. slang: perhaps from Port. mascotto, “witchcraft”), the term for any person, animal, or thing supposed to bring luck. The word was first popularized by Edmond Audran through his comic opera La Mascotte (1880), but it had been common in France long before among gamblers. It has been traced back to a dialectic use in Provence and Gascony, where it meant something which brought luck to a household. The suggestion that it is from masqué (masked or concealed), the provincial French for a child born with a caul, in allusion to the lucky destiny of such children, is improbable.