I remember a long time ago I read a story about a woman and her snake. This woman had a python snake as a pet.
The snake was with the woman since she was very young. The woman pampered her friend in such a way that he was always accompanying her everywhere she went. While working, cooking, bathing. She even got the snake used to sleeping next to her.
And so the snake grew with its owner and eventually became an adult. Its owner was very proud of her pet because each day the snake detached itself less from its owner's side, it wasn't leaving her alone at all! She thought the snake learned to love her as much as she loved it.
She often told her friends that her Python never left her alone, She said that the snake always wanted to be very close to her body.
It continues to grow, it almost reaches the length of its owner (when laying down that is). The woman began to notice a never-before-seen behavior in the way her pet sleeps, now the snake sleeps next to her but no longer rolling up in, now it sleeps with its body fully stretched out... but always next to its owner.
As the days go by the woman notices that the snake does not change its position and keeps sleeping fully stretched out next to her. She decides to visit a snake expert in a serpentarium, she consults the specialist about the change of behavior of her pet Python.
The specialist tells her, very fluently, "This type of snake is carnivorous, it's innate in them to learn to hunt from the moment they are born. They are always taking advantage of opportunities, what the snake is trying to do is measure your size and compare it to hers. When the snake considers that her size is right for her in relation to you, she will proceed to hunt you while you sleep. She'll wrap you gently with its body and then squeeze you as hard as it can and end up swallowing you. "
It's not that the snake is a bad or good being, it's just that its condition as a predator is natural, and nothing can change that part of its behavior.
I don't know if this is a fable, a story or something that actually happened... I only remember reading it once in my life.