Once upon a time...
...probably in India, where all fairy tales come from...
Uma, a young peasant wandered through the forest gathering berries, when he saw a little snake being attacked by a big bird who also was out for lunch. Whatever made the peasant shoo away the Garuda? He surely was no Christian who would have stood and applauded. Maybe an abstract sense of honor.

Or maybe the fact that the little snake wore a little crown.

SSSSSHAZAM! The snake turned into a beautiful maiden. (Definitively India.) "I'm Nigi, the Naga princess. I owe you my life. I think you deserve an instant reward." And since she was dressed for that reward anyway (i.e. completely nude - taking clothes with you during shapeshifting is a very advanced magic) on the spot they did it like rabbits, and since Nigi thought the reward still wasn't enough, she turned into her Naga form, wrapped around Uma and gave him a blowjob to remember.
"Nigi", Uma panted (she had an embrace like a ten foot anaconda), "I fell in love with you. Take me to your father so I can court for your hand."
"Courting for the hand of a snake, now that's a good Zen koan if I ever heard one!" Nigi giggled. "But I fear if my father hears that request, he'll send a cobra to bite off your dick, and that will be a blowjob not at least as pleasant as mine. And I don't even want to think what he does when he is in a bad mood."
Umas dick shrunk to a quarter at the sordid news.
"Well, maybe I can do something for you. Do you know the Enigma Princess?" "How shouldn't I know? About every boy in my hometown has got lovesick and tried to accomplish her marriage task. And failed miserably. Their heads now decorate her castle."
"A very ugly way to give head, indeed."
"And the left-alone maidens are so lovesick that even the most poisonous vipers have fled the area."
"Now you can see why I will help you win the game. Granted, she isn't as pretty as me..." Uma didn't veto. You don't talk back to a Naga princess wrapped around you if your ribcage is of any value to you.
"...but anyway, it's the next best thing. Deal?"

"Hereby it's proclaimed that insert name of idiot here..." "Uma!!"
"that Uma wants to marry the pretty virgin Turandot and fulfil the task first she has set for him, otherwise the poor sod is beheaded, over roger and wilco." The herold blew his trumpet, and Uma stepped forward.
"So here is your task. Dead simple. Hide from me. If I give up, you win. If I find you, skkkrk." Turandot moved a finger along her throat. "Three hours for both of us. I now take my beauty sleep while you run for cover. Nighty-nighty!" And off she was.

Uma headed for the next janitors closet where Nigi already waited for him. As a little snake, she could easily bypass all guards.
"Oh, you are so predictable. Don't even had to use my infrared sense to find you here. Hint: Turandot isn't playing fair. She owns a magic mirror which shows her all kingdoms, earth, water or air. She'll spot you in ten minutes even if you entrench yourself on the moon. But two can cheat in this game. SHAZARELLA!"
And before you could say It's no trick, it's a Sony Uma had been turned into a snake too.
"I granted you all Naga powers. You can change your size from giant Python to tiniest earthworm at will. Or turn to Naga form. Or back to human. You don't even have to chant silly magic formulae, that was just for show."
"Will her magic mirror still be able to view me?"
"Oh yes, it will. Unless you enact part B of Ye Masterplan which is finding a very good hideout. One only snakes visit."
"Snakes? But what..."
"Trouser snakes." Nigi grinned up to her ears...only that snakes have no ears.

Uma crawled up the bedpost where Turandot was dreaming happy dreams of falling heads. (Quite into S&M, that babe, eh?) He sneaked into her undergarments and reduced his size to the lowest level he could manage. "Don't enter her as a giant python. Leave that for your wedding night. And it's not only because you'll wake her. That magic mirror has a fatal flaw: it can't look into a virgin."
Uma couldn't resist to lick Turandots clit with his forked tongue. Very fast, she got dripping wet and opened wide. Still deeply in sleep, her hand found her clit. Now this wasn't part of the plan. Quickly, Uma glid into Turandots vagina and squirmed past her cervix into her womb. It was a matter of seconds as Turandot had stimulated herself into an orgasm and her vagina walls contracted so hard that this would have been the end for Uma.

"Ooooh, what a pleasant dream. Time's up, Uma, I'm coming! That is, I'm coming again, hahaha! Mirror! Show me his hideout!"
The mirror replied: "I can't!"
"What does this mean, you can't! Do it! Immediately!"
"A fatal error occurred in process #01. Core dump: AFFED0D0..." Turandot threw the mirror on the ground where it fragmented into loads of blue shards.
"Where is the bastard? Ah, probably only a magic malfunction. Best I look into the janitors closet where all the other idiots were hiding."
And Turandot ran frantically around her castle while Uma, from his safe place, snickered: "Tepid! Cold! Arctic! Supraconducting! Einstein-Bose condensation!"
After the three hours were over, Turandot broke together on her bed, exhausted. "Where are you? Come out!"
Uma wanted to extend the game a bit and increased his size. Turandot felt a squirming inside her that was almost pleasant. She ripped off her clothes. And then it dawned to her. Umas snakehead parted her labia from inside and he mocked: "Peekaboo!" "Eeeek!" Turandot squeaked as her virgin blood was spilled. "You pervert! You cheat!"
"Sore loser, aren't we? Nothing in the rules. About that. Or, for example, magic mirrors."
"Get out of me! You had help! I will..."
"You will marry me, happy ever after, etc pp, and if I have to tame you first..."
Uma bit Tutandot gently into her clit. A special poison flooded her vains, paralyzing her and making her super-horny at the same time. Uma changed back into his human form and shagged her through. And since her eyes still looked defiant after a few orgasms, and the poison was already wearing off again, he changed into a giant anaconda and squeezed her into his coils. Her screams were sealed shut with his big inflatable hemipenes. His forked tongue flickered over her clit, and his grip contracted gently. Turandot hardly couldn't breathe anymore. With a last super-orgasm, she passed out, her will broken forever.

Nigi entered the scene again when Uma unknotted himself from Turandot. "Ouch. That will give a few bruises. Maybe you should have hypnotized her instead. Well, it's irrelevant anyway. Lucky news! When my father heard my story, he said I should marry you since the Naga people would need some fresh blood. His aunt is an albino and...I guess our dynastic questions are boring to you, let's have some more sex!" And they did it in human form, and then in snake form, and in naga form, and then Turandot awoke from her blackout, and since the three found no local law against polygamy, they had even more sex.
The Kamasutra had to be extended by a hundred positions that night.

Uma, Nigi and Turandot stood in front of the castle and looked upon the massacre.
"OK, you're the master and I repent for my wicked ways. But this won't make all those poor peons alive again!" Turandot sobbed.
"Aw, shut up, you big crybaby!" Nigi snapped. "My grandfather is a Black Mamba and an expert on Black Magic. Watch this." She whistled through her fingers, and an army of snakes appeared. They gnawed themselves through the skulls and into the brains of the victims. "Shazalamadingdong!"
"Hey? Aren't I supposed to be dead?"
"What happened? How did I turn into a snake?"
"There is Turandot! Sic her!"
"Shazapp, eh, I mean shaddap! I haven't reincarnated your souls into these snake bodies so you can start the feud again! Forgive and forget, or you can kiss your Karma goodbye! Everybody slither home, some love-starved maidens are longing for you!"

And off they went, and soon you could hear delighted squeals from everywhere. (Bless the forked tongue.) That night went into history as the "Big Cum". Nine months later the Naga people hadn't to worry about inbreeding problems any longer. And apart of the fact that this is all a big cop-out, everybody lived happily ever after.

The End