How the bee got his knees
"'Bee's knees' is actually one of a set of nonsense catchphrases from 1920s America, the period of the flappers. You might at that time have heard such curious concoctions as 'cat's miaow', 'elephant's adenoids', 'tiger's spots', 'bullfrog's beard', 'elephant's instep', 'caterpillar's kimono', 'turtle's neck', 'duck's quack', 'gnat's elbows', 'monkey's eyebrows', 'oyster's earrings', 'snake's hips', 'kipper's knickers', 'elephant's manicure', 'clam's garter', 'eel's ankle', 'leopard's stripes', 'tadpole's teddies', 'sardine's whiskers', 'pig's wings', 'bullfrog's beard', 'canary's tusks', 'cuckoo's chin' and 'butterfly's book'. "