Princess Luna

Princess Luna is a fictional alicorn pony from My Little Pony: Friendship Is Magic, the younger sister of Princess Celestia, and co-ruler of Equestria, responsible for raising the moon. Initially appearing as the villain Nightmare Moon after a thousand-year banishment, she is redeemed and returns to rule alongside Celestia, often appearing in her subjects' dreams to help them overcome nightmares. She is characterized by her dark blue coat, starry mane, and crescent moon cutie mark.