She's part of a species called "Felloresian Warrior Snakes" That has a natural home in the Felloresian Forest of my world. These snakes are named such a way because humans long ago used to hunt for these snakes, and the rumors around were if you managed to catch one and live to see the next day that you were deemed worthy of being called a warrior. These snakes have nearly the same level of sentience of a human, but they are bigger than a human. They also feed on humans, but this character... Kay doesn't like that at all. She liked humans and hated that she'd have to eat them too. Thankfully she didn't live close enough to a human city or village to be tempted. She just fed off the wildlife!

But soon after befriending a human girl her mind changed. "I can't live with the temptation," she said, and with that, she traveled towards the mountains to meet a powerful Maika. (Basically a fairy.) This Maika grants one wish per person, and her wish was to be able to feed naturally without killing a single creature. The Maika was surprised, even a little confused, but kept his promise. With a blink of an eye she had felt cramps all inside-- what was happening?? ..he explained he had his own way of fixing the problem, but it wouldn't be nice. She still had to eat living creatures, but he hesitantly explained she'd only feed on carbon energy. (Like carbon dioxide is used oxygen, carbon energy is used energy.) She can eat an animal, and when she feels well enough, is able to release it.

This was a bit uncomfortable for her, but at least it meant she didn't have to kill anything... In the end, she met a new human, a boy, and they became best friends, she spoke to him every day and eventually ended up living with each other. She's happy he isn't in any harm around her...