"But I must be paid also," said the witch, "and it is not a trifle that I ask. You have the sweetest voice of any who dwell here in the depths of the sea, and you believe that you will be able to charm the prince with it also, but this voice you must give to me; the best thing you possess will I have for the price of my draught... Put out your little tongue that I may cut it off as my payment..." - "The Little Mermaid" by H.C.Andersen.