Princess Ludovine is the antagonist of the French fairy tale "The Little Soldier", originally written by Charles Deulin and later included in The Green Fairy Book by Andrew Lang.
Princess Ludovine, the daughter of the King of the Low Countries, is first encountered in the form of a hideous snake with a woman's head. After John restores her, she is a beautiful woman with blonde hair and green eyes. But her beauty belies a selfish, greedy personality. She gives John gifts, but these only lead him to fall asleep, and she later steals his purse and mantle.
John, a soldier returning from war, encounters Prince Ludovine in a ruined palace. She is in the form of a serpent, but when he restores her, she gives him money, tells him to wait at the inn, and promises that she will come the next morning. She promises to marry him afterwards, and gives him a mantle and a purse of money.
John believes Ludovine at first. First, she gives him a golden drink, and says she will come at 9 AM the next morning. But when John drinks it, he sleeps through her visit. She then gives him immortelles, and says she will come at 8 AM next morning. John takes them and sleeps through the visit again. Finally, Ludovine gives John a flower-colored scarf, and says she will come at 7 AM next morning. Once again, John sleeps through the visit. He does not see Ludovine for a while, but he later meets a kind young fisherwoman known as the Seagull.
Eventually, John puts on the mantle and wishes he was at the palace of the King of the Low Countries. To his surprise, he arrives at the palace. Ludovine sees John the next day, but turns away from him. Several days afterwards, John plays cards with Ludovine and her parents. When they realize that John's purse always replenishes (which is why he is able to pay off his losses), Ludovine calls it bewildering. John retorts that it is not as bewildering as Ludovine's change into a serpent. John tells the king that he saved Ludovine and that he is the son of a boatman. The king refuses to consent to the marriage unless John gives Ludovine his purse - which he does. They agree to marry on Easter.
However, John later sees Ludovine counting his money from the purse. John asks about the marriage, and Ludovine refuses to marry him - or give the purse back. She later steals the mantle as well.
John plots his revenge by disguising himself as a merchant and selling her plums that can give her deer horns. Ludovine eats the plums and grows horns. She throws a tantrum, ordering John to be killed. John later disguises as a doctor and gives her plums that will remove the horns. When Ludovine is cured, she reluctantly returns the mantle and purse to John.
John then reveals himself to Ludovine, telling her that he should have left her with the horns, but she was too much like the devil to have any. John then puts on the cloak and returns to the Seagull, who proves to be a much better choice for a wife than the princess. The two dispose of the mantle and purse by throwing them into the sea.
[http::/www.mythfolklore.net/andrewlang/369.htm Text of The Little Soldier from The Green Fairy Book]