Disclaimer: I don't own Nagini, Hogwarts or Voldemort. This is written for hillstar's 'Character Appreciation Challenge'.
AN: Magical snakes have more of a family bond than normal snakes and live for a long time.
The Human
Nagini had always been an inquisitive snake. The nest at home with her brothers and sisters had held little entertainment, so she began to explore the forest. Her mother had told her not to: there were birds and Griffons that could tear her apart in seconds and human hunters too, but Nagini didn't care. She was bored and the black forest was so inviting.
She slithered happily through the undergrowth. The shrubs were tall and mostly covered her so there was nothing to worry about. Her mother was silly to worry about predators; nothing would want to eat Nagini – she was the Queen of the forest.
She moved silently, slipping and sliding smoothly along until she reached a small, sunny spot where the sun shone down and lit up the leaves covering the ground. However, it wasn't the lack of canopy that stopped Nagini, nor was it the sudden difference in light. What stopped her was the presence of the human.
Her mother had always told her that humans were dangerous, deceitful creatures. They would come to the forest with nets and take away the baby snakes. That was what had happened to Nagini's mother's brothers and sisters and why she had been warned never to go near them. However, Nagini was fascinated by them. The humans had their own language: one too primitive for snakes to understand, but Nagini's mother had told her that once-upon-a-time there had been Great Wizards who could speak to snakes. Nagini had always been captivated by her mother's stories and the talking magic people had been one of her favourites.
She watched the human. It was digging, but not in the way a mole would. A mole was an extremely primitive creature and rather tasty. No, the human has holding a stick between its paws and was simply pointing it at the pile of accumulating dirt. The hole was digging on its own. Nagini watched a little longer until the human reached down into the hole and brought out a box. It was then that the human looked up from the hole and noticed her.
Its dark eyes stared at her, and Nagini stared right back. There was something intense about them that drew Nagini in, as if there were some connection between them.
"Hello, little snake," the human said.
"Hello, human," Nagini said. Even though it was the first time she'd seen a human, she wasn't afraid. The humans that could talk had always been good humans in her mother's stories. "You can talk, that's unusual for humans."
The human laughed, but not unkindly. "I'm a Parselmouth, so I can speak to snakes. It's a rare talent, but not unheard of among wizards."
"Oh, are you related to Salazaar Slytherin?" Nagini mentioned the most prominent magical human from her bedtime stories. "He's my favourite."
"He's my Ancestor," said the human.
"Tell me more," said Nagini. Nagini was enthralled as the human told her more stories about Salazaar Slytherin in so much more detail than her mother had told her. Over the course of the conversation, she learnt that the man's name was Tom Riddle and that he hated his name: the name of a non-magical human that couldn't speak to snakes. She also asked about the box, which she learned contained the lost diadem of another ancient magical human.
When Nagini returned to her mother it was quite late and the sun was setting. Her mother was relieved that her nestling had come home and forgot all punishment. It was thus that Nagini set out at the crack of dawn the following morning to meet with Tom Riddle. All day, Nagini enjoyed stories of the magical school called Hogwarts. She especially liked the story of the giant Basilisk that roamed the school and lived in a secret chamber.
…..
After the second encounter, Nagini's mother found out about where she had been going and decided to keep a watchful eye on her. Humans were dangerous, she'd repeated, even magical ones. It was therefore weeks before Nagini was able to slip away again.
This time something about Tom Riddle had changed. His eyes showed a glint of red and there was something about his presence that felt a little "off", as if not quite all of him was there. Nagini wondered what had happened to her Tom Riddle to make him lose a part of himself. However, once they started talking, he seemed much the same.
This time Nagini asked how the wizards lived when they weren't at Hogwarts, for she had never seen any kind of society, let alone a wizarding one. Here in the deep forest, the only humans she knew about were hunters and her mother had always made sure that they stayed well away from them. Nagini asked what Tom Riddle wanted to do with himself now that he had left Hogwarts, and it was this that had prompted their goodbye.
"I'm afraid I will have to leave for a while. I've got an interview at my old school, Hogwarts, to become a teacher there. "
"Will you come back?" Nagini asked. She was glad that he would have the chance to go back to the school that he had loved so much, but she would miss him.
"I will one day," said Tom Riddle.
…..
It was decades later that Nagini saw Tom Riddle again. Nagini was now an adult and longer than he mother had ever been. She'd missed him. Compared to the magical human, snake conversation was listless and dull.
She sensed his presence before she saw him, but when she reached him he was little more than a wisp. He'd become a shadow of the human she had met as a nestling but it was still him. She could sense that.
She slunk closer. His scent on her tongue held the same signature as before but now even more parts of him were missing. Something awful had happened: another wizard had done this to him perhaps.
She heard his voice in her head. So weak that it almost wasn't there. "Help me," he was saying.
"How?" she asked. "You're so thin you can't even touch me. How can I help you?"
"I need a little of your strength. Take my spirit for a while until I can find myself another body," Tom Riddle said.
Nagini wondered how such a thing could be possible. How could the wizard find himself a second body? However, she allowed the spirit of the man she once knew to touch her, and with that touch, the wizard's mind merged with her own.
Immediately, all Nagini saw were memories. A green flash of light, a crying baby, a red haired human, followed by many images of fighting wizards, Hogwarts, and finally the orphanage where Tom Riddle had grown up. When they finally stopped, Nagini had learnt all about the war, the new name of Lord Voldemort that her Tom Riddle had taken for himself, and felt anger at the baby who had taken it all from him. She knew deep down that some of what she was feeling belonged only to Tom Riddle and not her, but the feelings of anger and hatred and anger were overwhelming. She kept calling him Tom as a way of separating their thoughts from each other and as a way of remembering the man he had been before he'd left her.
Her mission was now clear: a plan had been hatched for Tom Riddle to possess the first human they found that could help defeat that baby (who was now a child after the many years that had passed since that incident). The first chance they got was a young wizard, due to take up the same teaching post that Tom Riddle had failed to get all those years ago. Nagini could still feel Tom's anger over that even now.
When Tom Riddle possessed the new Professor, Nagini followed him to Britain to wait for the plan to work. She waited in a new forest just outside Hogwarts to join him when he became human once more.