They look pretty enough when they sit upon a rock, twanging their harps and combing their hair, and sing, and beckon to you to come and hold the looking-glass; but when they sink into their native element, depend on it, those mermaids are about no good, and we had best not examine the fiendish marine cannibals, revelling and feasting on their wretched pickled victims. 
They look pretty enough when they sit on a rock, twanging their harps and combing their hair; but when they sink into the sea, depend on it, those mermaids are up to no good, and we had best not examine them feasting on their wretched pickled victims. 