Princess Luna

Princess Luna, the Princess of the Night and Princess of Equestria alongside her older sister Celestia, is an alicorn who has a dark indigo body, an eternal dark blue mane and tail, and teal eyes. She has a large cutie mark showing a white moon in a black background, and speaks with a mild English accent. As "Princess of the Night", she possesses the ability to enter ponies' dreams and help them face their fears. She raised and lowered the moon each night, but she became jealous of Celestia because the ponies slept through the night and thus did not appreciate her work. This jealousy eventually transformed Luna into Nightmare Moon. Celestia banished Nightmare Moon to the moon after she tried to bring eternal night to the world. When Nightmare Moon escaped her imprisonment on the moon she returned to Equestria where the six mane characters use the Elements of Harmony to transform her back into Luna whereupon she resumed her place at Celestia's side.

In the alternate world shown in My Little Pony: Equestria Girls, she is known as Vice-Principal Luna, and helps her sister, Principal Celestia, run Canterlot High.

Pricess Celestia

Princess Celestia is the "Princess of the Day" and primary ruler of Equestria alongside her younger sister Princess Luna. Princess Celestia is an alicorn who controls the rising and setting of the Sun. For a millennium, she also controlled the moon while her sister was banished. She has a white coat with a hint of pink and a pink, violet, green and cyan eternal mane and tail and purple-pink eyes. She wears a gold tiara, collar and horse shoes. She has different wings compared to the other three princesses and she possesses the longest horn. Her cutie mark is a large sun symbol. Princess Celestia is usually very kind, patient, and understanding. She wishes for her subjects to relax and be themselves around her, despite her status. She is also sometimes somewhat mischievous. She has a pet phoenix named Philomena, appearing in "A Bird in the Hoof". Celestia is taller than all other ponies in the show.Celestia often refers to Twilight Sparkle as her "most faithful student".

In the alternate world shown in My Little Pony: Equestria Girls, she is known as Principal Celestia, and is the head of Canterlot High.