Starlight is not a character in My Little Pony, but would bring a fine twist to it. She is an alicorn, but she is not a princess. She is from another pony world, Hiloria. Hiloria is a pony world contaning only alicorns. Starlight's best friend is Kayacoh (kay-a-coe), an earth pony from Arabia, and came to Ponyville after she got lost on her way to Manehaten, and lived there ever since.
Her Cutie Mark is a raincloud.