Then your tail will divide and shrink until it becomes what the people on earth call a pair of shapely legs. But it will hurt; it will feel as if a sharp sword slashed through you. Everyone who sees you will say that you are the most graceful human being they have ever laid eyes on, for you will keep your gliding movement and no dancer will be able to tread as lightly as you. But every step you take will feel as if you were treading upon knife blades so sharp that blood must flow. I am willing to help you, but are you willing to suffer all this?""Yes," the little mermaid said in a trembling voice, as she thought of the Prince and of gaining a human soul.
Hans Christian Andersen, The Little Mermaid
leg, love, pain, witch