moon-calf (n.)youdaoicibaDictYouDict[moon-calf 词源字典]
also mooncalf, "abortive, shapeless, fleshy mass," 1560s, attributed to the influence of the moon; from moon (n.) + calf (n.). In later 16c., "deformed creature, monster."[moon-calf etymology, moon-calf origin, 英语词源]