AN: I know that there aren't a lot of crossovers between Naruto and Monster-girl, and I've read every one of them that's in English. This one is going to be very unique in the fact that Naruto does not replace Kurusu and he does not join the MON Squad. This actually involves some experimentation by Orochimaru. Therefore if you don't like seeing Naruto being changed drastically then don't read this story and don't flame. This is my first crossover so I can only hope this turns out good. In this case Orochimaru is more focused on creating interesting creatures to attempt to control than he is in immortality.

So, without further ado let's start the story.

Disclaimer-I do not own either of the mentioned manga

The Snake Boy

Prologue

Unknown location

The second he awoke, he knew something was wrong. He felt weak and he couldn't seem to access his chakra. He remembered fighting Sasuke at the valley of the end. He could remember the massive black ball of energy as their most powerful attacks collided. He even remember barely being able to keep his eyes open as he watched Sasuke start walking away toward the land of rice. But now as he woke up he realized that something must have happened after he passed out because he was currently strapped to some sort of operating table in a dark and dim room that had walls made of concrete. He could barely keep his eyes open but he knew that he had to stay awake if he wanted to find out what was going on. As he was focusing on staying awake a door that he couldn't see opened and man with long black hair, pale white skin, and yellow eyes like a snake walked in and came up to Naruto's side. The problem was that Naruto was so tired and weak that he couldn't even muster the strength to glare at the man. Naruto knew that the snake must have had Kabuto kidnap him after the fight to experiment on him but he didn't know why. As he was thinking these things, Orochimaru started talking.

"Now I'm sure you remember me and I'd be willing to bet that you're wondering why you are here. So I'm going to tell you. You're here to be a test subject for an experiment that I want to try out involving the DNA of a creature from beyond the veil that I found most interesting. It had the upper body of a human with the lower body of a snake. I am going to see what happens when I constantly implant parts of its body and blood into you. And if you survive and have any useful changes I will train you as my pet. And now that you're awake we can begin the first series of injections and implantations." Orochimaru hissed out slowly as he started to make incisions in naruto's body and insert fragments of what looked to be snake scales into his body. Naruto was awake the entire time and could feel the pain of every incision. When Orochimaru was finally done he stuck a needle in Naruto's arm that led to an IV that must have been filled with the creature's blood. It was at this point that Naruto was finally able to pass out from the pain.

3 months later

Over the past several months, which felt like years to Naruto, slight changes were happening, but they were only slight, his pupils changing to slits, his ears growing long and pointed, growing snake-like scales on his cheeks and his whisker marks fading from existence. Do to these only slight changes Orochimaru was losing patients. The last straw was when Naruto lost all feeling in his legs, making them completely useless, and also lost the ability to use chakra. Assuming the experiment was a failure he delegated the task to continue the work to some of his more minor underlings. Orochimaru never even returned to that base until 3 years later and by then, it was already too late.

Little did Orochimaru realize that the people now in charge of the experiment were far more sympathetic than himself and started to teach Naruto about what they knew of the creature that the DNA was from. According to them, it was something called a lamia and that they were from somewhere beyond the veil.

3 years later

It wasn't until about the first year that the big changes wear seen happening. Naruto's legs started merging together morphing into something like a tail. The next week is when his 'tail' started lengthening to an incredible 8 or 9 meters long and grew bright yellow snake-like scales leaving only his upper body and genitals uncovered by them. The final changes included some sort of pouch forming where his genitals would be well protected and his canines growing longer and sharper. However, the least noticeable change and possibly most deadly were the poison sacks that seemed to grow in above his mouth. The one thing that several people expected to change but didn't was the temperature of his blood. Everyone knew that snakes were cold blooded but for some odd reason Naruto seemed to keep the hot blood he was born with, most likely based on the fact that the changes were occurring in an underground lab that was typically kept quite cold in order to preserve certain research material. However, what the researchers didn't know was that while Naruto was still himself, he had become very dangerous on a full moon when he was simply driven by instinct.

It was October of his third year in captivity that the full moon affected him so greatly that he managed to escape the bindings and silently slither his way through the base and injecting anyone he came across with a poison so strong that one drop was enough to kill a fully grown elephant. When he managed to find his way to the surface he immediately headed in the direction that he discovered was where the other side of the veil was.

Orochimaru returned to the base the next day to find it filled with nothing but corpses, each with two small puncture holes somewhere on their body that looked an awful lot like a snake bite.

-End

So tell me what you think. I can't guarantee fast updates but I can say that I already have pairings decided, I sure hope the main one is obvious.