The Little Girl that would not listen

In a little village in the shadow of the mountains there lived two families. Each a father and a mother and each with a single child. A boy and a girl, same of age but different character. The boy would always listen to what his parents would tell him. He let them cut his hair, cut his nails and cleaned his room.
The little girl, however, did not. Her hair reached her ankles, her nails poked holes into her socks, her room a chaotic mess. Whenever her parents would try to tell her something, she turned her back, put her fingers in her ears and began to sing:
NaNa NaNa NaNa NaNa NaNa
Day after day, week after week. No matter what they did, she was simply uncontrollable.
Then one night, while lying in bed, awake long after midnight, she heard a sound from her bedroom wardrobe. The door opened and a shadow approached. With a loud hiss, it jumped at the bed. Screaming the little girl tried to run for the door. But the floor was cluttered with toys and she stumbled and fell. A dark hand grasped her long hair and dragged her back.
She screamed and screamed and screamed but only the shadow answered:
NaNa NaNa NaNa NaNa NaNa - it growled in a scraping voice.
She was dragged into the wardrobe never to be seen again.

And that is why you always listen to what your parents tell you Mirus. Because the Shadow loves naughty children. Sleep before midnight so it doesn't notice you. Cut your hair so it can't grab you. Clean your room so that you don't stumble while running from it. Listen to what we tell you. Don't end like the poor girl in the story.

Vardanian Stories
Shadows are a common trope among Vardanian stories. Dark creatures, liquid shadows, monstrous human-like abominations, there is a large array of terrifying beings to be found. They hunt children and adults alike, however, those stalking young ones can usually be warded off by listening to the advice of one's parents.
Most of these stories are ancient and are commonly used to teach children basic functions like personal hygiene or how to deal with strangers.