Princess and the Frog
History
"The Frog Prince; or, "Iron Henry" is a fairy tale, best known through the Brothers Grimm's written version; traditionally it is the first story in their collection. The 2009 Disney film, The Princess and the Frog, is loosely based on this story.
The Real Story
In the tale, a spoiled princess reluctantly befriends the Frog Prince (meeting him after dropping a gold ball into a pond), who magically transforms into a handsome prince. Although in modern versions the transformation is invariably triggered by the princess kissing the frog, in the original Grimm version of the story the frog's spell was broken when the princess threw it against a wall in disgust.
In other early versions it was sufficient for the frog to spend the night on the princess' pillow.
The frog prince also has a loyal servant named Henry who had three iron bands affixed around his heart to prevent it from breaking in his sadness over his master's curse, but when the prince was reverted back to his human form Henry's overwhelming happiness caused all three bands to break, freeing his heart from its bonds.