This pony, though she looks just like Applejack as a filly, is actually an OC character I created for a ‘Choose Your Own Adventure Thread Quest’ I did a couple weeks ago. Her name is Canvas.
In the context of the quest, the player got teleported to Equestria and enjoys their new life for about a solid week. Then, all of a sudden, they are being stalked by some demonic looking creature that causes them to feel absolutely horrible. It speaks in screams and empties their world of happiness. Of course, this demon turned out to just be little Canvas here. She had gotten her hooves on a magical hairpin that Zecora dropped during one of her visits to Ponyville. When worn, it causes humans to see abominations of the creature that is wearing it. Also, if the player attempted to touch/contact the wearer or the pin directly, they were turned to stone.
3 Anons died during the quest. It was one of my best one’s written to date.