Twilight Sparkle is the central main character of My Little Pony Friendship is Magic. She is a female unicorn pony who transforms into an Alicorn and becomes a princess in Magical Mystery Cure. She is also the daughter of Twilight Velvet and Night Light, the younger sister of Shining Armor, sister-in-law to Princess Cadance, and paternal aunt to Flurry Heart.
At the beginning of the series, she and Spike, her best friend and assistant, move from Canterlot to Golden Oak Library in Ponyville to study the magic of friendship, and in Twilight’s Kingdom – Part 2, she gains her own castle—theCastle of Friendship—and gains the title “Princess of Friendship”. Twilight Sparkle represents the element of magic.
Before becoming a princess, she regularly sends friendship reports to Princess Celestia. In Owl’s Well That Ends Well, Twilight adopts a pet owl named Owlowiscious.
Twilight’s human counterpart, Sci-Twi, briefly serves as an antagonist in My Little Pony Equestria Girls: Friendship Games.
Twilight Sparkle lives in Canterlot until Princess Celestia sends her to Ponyville. Accompanied by Spike, Twilight checks the town’s preparations for the Summer Sun Celebration and meets the rest of the main characters. The celebration is interrupted when Nightmare Moon, Celestia’s nemesis, returns to power and threatens to bring eternal night to Equestria. Twilight and the rest of the Mane Six discover the Elements of Harmony and use them to transform Nightmare Moon back into Princess Luna. Princess Celestia gives Twilight permission to remain in Ponyville to study the magic of friendship.