D is a very hefty chapter in the Motif Index: It stands for Magic. And everything magical, from transformations to items with special powers, speaking animals, and the like. You can find such things on the list as "D113.1.1. - Werewolf," "D395 - Transformation: Frog to person," or "D1093. Magic missile" (you're welcome, D&D fans) - and these are just the most mundane of the lot. Kissing a Frog Prince suddenly sounds a lot nicer when you compare it to:
D192.2. Transformation: man to centipede
In the Korean folktale spoiler-tastically titled The Centipede Girl, a poor man, incapable of supporting his family, decides to end his life and jumps from a cliff into a river. However, he does not die: He is rescued by a mysterious, beautiful maiden, who takes him to her luxurious home. The two of them fall in love, and our nameless protagonist spends quite a long time happy in the lavish love-nest.
Eventually, however, he does decide to visit his actual family, to see how they fared since he had left them. To his surprise, he finds them in a brand new home, wearing expensive clothing: Turns out someone had been sending them money regularly since the husband's disappearance. Content with the news and guilt-free (heh), the man decides to return to his gorgeous lover. But.
|Picture from here|
On the way back, a voice calls out to him from a hollow tree, claiming to be the spirit of his grandfather, and warns him that the beautiful woman is actually a thousand-year-old giant centipede, who has enchanted him with her illusions. The spirit suggests that the man should smoke some tobacco, keep the juices in his mouth, and spit them in the woman's face, to reveal her true nature.
The man sets out to do exactly that... but when he sees the perfect face of his lover, he changes his mind, and spits the tobacco out the window. The girl cries and thanks him, telling her story: She is the daughter of the Heavenly King, who has been seduced and slandered by a servant. As punishment, the servant was turned into a snake (hence the vindictive voice in the tree), and the girl into a centipede, to spend three years on earth. Her time is up the very next day, and our hero wakes up alone, lying on a bare rock...
So, the point is, she really was a centipede after all.
(Story from Zong In-sob's Folk Tales from Korea)
D55.2.1. Dwarf contracts self to enter nostrils of cannibals
D179.4. Transformation: man to shrimp
D211.2. Transformation: man (woman) to pomegranate
D222. Transformation: man to nut
D251.1. Transformation: man to saucepan
D412.3.1. Transformation: pig-fairy to fish
D415.1.1. Transformation: mantis to hartebeest
D435.1.4. Wax prince animated by serpent becomes human being
D439.6. Fire takes the form of a woman and runs away
D451.3.2. Transformation: coconut to philosopher's stone
D457.14.1. Transformation: ogress's tongue to surfboard
D476.3.2. Bacon changed to iron
D562.2.1. God's urine makes chilly fiery
D991.2. Magic pubic hair
D1023.4. Magic hair of ant's beard
D1359.1.1. Magic olive branch makes woman master in household
D1402.15.1. Magic poem (satire) causes man to melt
D1454.9. Treasure from nose (with sneezing)
D1511.1. Magic carpet cures drunkenness
D1610.3.4. Speaking egg-plant
D1610.6.3. Speaking buttocks
D1641.16. Bananas run and hide when stone is thrown at them