One possible ending is that the girl manages to get the dog suit off just in time and realizes it was all a hallucination caused by some sort of drug or chemical on the suit. Another ending could be that she is stuck in the suit forever and slowly transforms into a real dog - like creature, living a life in misery.
Once there was a girl who found an old dog suit in an attic. She put it on for fun, but as soon as she did, she started to feel strange. Her eyesight became blurry and she saw things that weren't there. She heard growling sounds all around her. She tried to take the suit off, but it seemed to be stuck. Every time she moved, she felt more like a wild dog than a girl. It was a terrifying experience that she would never forget.
Once there was a girl named Lily. One night, as she was walking home through a dark alley, a large, growling dog emerged from the shadows. Its eyes glowed red in the moonlight. Lily was terrified and froze. The dog started to slowly approach her, baring its sharp teeth. She tried to run, but her legs felt like jelly. Just as the dog was about to lunge at her, she saw a light from a nearby house and mustered the strength to run towards it. The dog chased her for a bit but then stopped at the edge of the alley.
Once upon a time, there was a strange old house. A girl was lured into it by a seemingly friendly dog. But once she entered, the dog's eyes turned red and it started to growl menacingly. The girl found herself trapped inside as the dog blocked the only exit. The room grew darker and colder, and she could hear strange whispers. She was so scared, not knowing what the dog or the unseen forces in the house would do to her next.
The fact that it moves on its own is really terrifying. In a normal world, suits don't move, but this one does. It defies our understanding of how things should be, and that makes it a source of horror. Also, if there are any strange noises or glowing associated with it, like the buttons glowing in the dark, it adds to the scariness.
The scariest part might be when the dog has some kind of unnatural or demonic look about it. Say, in a story where a girl encounters a dog with glowing red eyes and a strange mist around it. It gives the impression that this is not an ordinary dog but something more sinister. The girl doesn't know what this strange entity is capable of, and that uncertainty is extremely frightening.
Well, a dog can be scary in a scary story for several reasons. One is if it has some kind of supernatural element attached to it. Maybe it's possessed by an evil spirit, like in some stories where the dog can talk in a menacing voice or has the ability to disappear and reappear suddenly. Another aspect is the setting. If the dog is in a spooky place like an old graveyard or a haunted house, it adds to the scariness. And its actions towards people, like stalking them in the dark or attacking without provocation, can be really terrifying.
There was a store that sold second - hand clothes. Among them was a shabby - looking brown suit. A young man bought it without much thought. But as soon as he got home and hung it in his closet, he noticed something odd. The buttons on the brown suit would sometimes glow in the dark. And at midnight, the suit would make a rustling sound. One night, he woke up to see the brown suit standing upright at the foot of his bed, as if it had a mind of its own. He was so scared that he immediately threw the suit away.
Isolation is another theme. Maybe the story takes place in a remote area where the sight of a strange 'dog - human' figure is especially terrifying. The victim is alone and has no one to turn to for help when this horrifying entity shows up. It creates a sense of helplessness.
The desperation. A licking dog in a scary story is often so desperate for someone's attention or love that they will go to any lengths. This blind pursuit can lead them into dangerous and haunted places, like an old, spooky house or a desolate forest. It's the fact that their obsession overrides their common sense that makes them scary.