Apart from the name, Donkeyskin sounds exactly like something Disney would adapt into an animated feature. It's a rags-to-riches story about a runaway princess, complete with handsome prince and happy ending. The only real obstacle is the part with all the incest.
Our story begins with a prosperous royal family. The king in particular was feeling pretty good about his lot in life, what with his beautiful spouse, a loving daughter and -- no joke -- a donkey that pooped gold. But as they say, nothing donkeyshit can stay, and one day the queen fell suddenly ill. The sickly monarch told the king that, if he should ever find a woman as smokin' hot and wicked smart as she, he should marry her immediately so the royal bloodline could continue. Unfazed by the unreasonable and downright vindictive deathbed demand, the king started the hunt for his wife's replacement soon after her death.
Though he searched high and low, the widowed king could find no woman quite so bangin' as his lost love. No woman, that is, except his daughter.
Faced with the prospect of forcing his child into a life of incest or breaking an abhorrent promise he made to a dying woman that was possibly hysterical from illness, the king decided that he should probs marry his own daughter. She was understandably more than a little skeeved out about the situation. The princess consulted her fairy godmother, who apparently was out of town when this girl's mom was dying. Ol' FG recommended that the princess declare impossible requirements be met before the marriage could go forward. In particular, the princess requested three dresses of divine quality -- one the color of the sun, another the color of the moon and the last the color of the sky. She topped off the demands with the skinning of that magical gold-shitting donkey, just for kicks.
Much to the princess' surprise, the king had no problem fulfilling her wish for a yellow dress, a white dress and a blue dress. Even skinning a magical problem proved no problem for His Majesty King Creepazoid. Terrified at the prospect of her future life in the palace, which involved -- and I cannot stress this enough -- fucking her own father and having his children, the princess fled the castle. She used the donkey skin as a disguise, figuring that anyone who saw such a sight would mistake her for a crazy uggo that was a little too into the movie Freddy Got Fingered.
The newly-christened Donkeyskin toils in bakery peasant obscurity, making sure to play a game-of private dress-up with the dresses she stole before ditching the castle. It was only a matter of time before a handsome prince caught a peek, mired her self-mirin', and vowed to wed this girl by virtue of (what else) looks alone. To be fair, Donkeyskin was ironically just as superficial, because the feeling was mutual.
The prince requests that Donkeyskin make him a cake at the bakery, and in the process of doing so, she slips one of her fancy princess rings into the batter. Her plan worked, at least somewhat, as the prince totally flipped out and declared that he would marry whoever so fit the ring -- instead of you know, going directly to the girl he saw and getting down on one knee.
The Cinderella scam works anyway, as the ring fits Donkeyskin and the two are promptly married. Her father comes to his senses and apologizes, and everyone lives happily ever after... with the nagging feeling that the king probably still wants to bang his daughter.
This French fairy tale kicks off with a pair of miserly parents trying to figure out how best to rid themselves of the children that are emotionally and (most importantly) financially sucking them dry. The parents, whose first act of cruelty towards the children was naming them Jean and Jeannette, proceeded to leave their own kids in the forest to die. The newly-orphaned siblings quickly found a red cottage and were taken in by a kindly old lady, who warned the pair that her husband was a nasty guy who had a fondness for dining on prepubescent flesh. It might go without saying, but this child-foodie also happened to be The Devil.
Mrs. Satan was still on the kids' side, so she hid the two of them away. But the Prince of Darkness prided himself on his ability to sniff out lemony scent of Christian purity, and so he snatched the children and threw them into the barn to fatten up for what should have been a delectable human gumbo. This is the part where Jean and Jeanette use the ol' Hansel and Gretel trick; when the Devil came by to check on their plumping progress, the kids would stick slender objects (like a rat tail) through the crack of the barn door to make it seem like they were still stringy and altogether uneatable.
Satan eventually caught onto their little scheme, and was so furious that he told them to sit on a sawhorse to bleed. If you're unfamiliar with what a sawhorse is, it's one of these:
It looks like a harmless piece of woodworking equipment, but if used right, it can be a pretty awful torture device. The idea is that the victim would straddle the bar at the top, and since their feet wouldn't touch the ground, their genitals would slowly be crushed by their own weight. You know, for kids!
Since Satan took this time to go take a rage-walk, Jean and Jeanette were able to trick his spouse into thinking they weren't sure exactly how to sit on the sawhorse. When Mrs. Satan obliged their request for a demonstration, the pair pounced, tied her up and then slit her god damned throat. It's a pretty brutal end for an old lady that was initially trying to help save those children, but you don't say "I Do" to Lucifer without considering the idea that you might one day be cut open ear-to-ear by a pair of ruthless children.
After snagging some goodies from the Devil's gold and silver hoard, the kids bolted from the red cottage. Though Satan was hot on their trail for a while, he eventually drowned in a river, because Satan can apparently do that. Jean and Jeanette inexplicably returned to their parents' home, who presumably continued to be huge pricks who don't deserve to raise children.
The moral of the story: Nothing makes sense and everything is terrible.