AN: This is another Naruto one-shot, set in the Forest of Death during the Chunin Exams. The rest can be inferred.
"You have impressed me somewhat", said Orochimaru. "I believe you have earned this 'gift' (ku ku ku)". With an evil smile, the sannin's neck lengthened, covering the distance between the snake-man and the red chakra-covered youth. Orochimaru sunk his teeth into a surprised Naruto's neck. As he withdrew, three black marks appeared on Naruto's skin as a fragment of the snake sannin's soul was injected into his body.
Enter mindscape
Naruto opened his eyes to find himself in the familiar place before the Kyuubi no Kitsune's cage. While the demon wasn't making an appearance, an incredibly effeminate snake-like man stood facing Naruto, hands behind his back with an insane grin on his face.
"What the hell are you doing in here, you hebi-teme!", Naruto yelled angrily.
"Devouring your eternal soul; what else?" Orochimaru replied rhetorically in a sickly-sweet voice.
With an animalistic roar, the blonde launched himself forward, taking the sannin by surprise, and slammed his shoulder into the man's gut, hurling him in between the widespread bars of the cage behind him. Orochimaru rose quickly and began to taunt the young ninja. "This pathetic excuse for a cage can't hold me."
The boy in stab-me orange had a shit-eating grin on his face as he pointed over Orochimaru's shoulder. "But he can."
Those three words spelled DOOM for the despicable man in big fiery letters.
Orochimaru turned around in time to watch two huge, red eyes appear from the darkness, followed by a grin identical to the demon's container, but with huge, sharp teeth.
"Mmm, you know ningen, it's been quite awhile since I've had a bite to eat…" A large clawed paw shot out of the darkness and swept the now shivering Orochimaru into the dark, followed by the demon's eyes and teeth. The only sign of 'life' was the bloodcurdling screams of the snake-man; Naturally, foxes liked to play with their food when they weren't in a hurry, and Kyuubi had all the time in the world…
Exit mindscape
Orochimaru smirked as the blond Jinchuuriki blacked out from the application of the Cursed Seal of Heaven. He turned to look at the boy's teammates, who were frozen in fear. Suddenly, Naruto stood up while Orochimaru collapsed on the ground, screaming in agony as he felt the torture of his soul fragment.
Naruto grinned down at the sannin and said, "Don't fuck with a Jinchuuriki. Believe it!"
AN: Of course, if Naruto got bit in the manga/anime, Sasuke would have somehow gotten an even bigger power-up, just so that the 'good guys' wouldn't have the advantage. At the risk of sounding racist, I think it's a Japanese thing. And, as to the writing, this was a crack-shot (puns!), so I don't feel guilty about less-than perfect grammar, punctuation, etc...