Starlight Glimmer is a main character and former villain in the animated series My Little Pony: Friendship is Magic. She is a light purple unicorn.
Before her redemption, she was the founder and leader of a mysterious village where everyone has given up their cutie mark. After she was defeated by the Mane Six, she uses a time travel spell from Star Swirl the Bearded to stop Rainbow Dash perform her Sonic Rainboom and change Equestria's history. Twilight Sparkle and Spike follow her to stop her and fix the multiple timelines she creates. Twilight brings Starlight to an alternate future to show her the error of her ways. Twilight and Spike are then brought into the past by Starlight to show them why she wants to stop the Rainboom. She tells them that when she was young, her childhood friend Sunburst got his cutie mark and left for Canterlot, leaving her without a friend and a fear of making any new ones. After bargaining with Twilight, Starlight decides to allow the rainboom to occur, restoring the present day. After returning to the present, Starlight realizes the error of her ways, and is accepting of whatever Twilight gives her. Instead of a punishment, Twilight decides to teach Starlight the magic of friendship and have her join the Mane Six.
Through the sixth season, Starlight is taught friendship lessons by Twilight and tries to prove herself to the rest of Ponyville that she can change. She later graduates at the start of the seventh season, after saving Twilight and her friends from Queen Chrysalis. In the eighth season, she is the guidance counselor of the School of Friendship; she soon gets promoted to headmare in the final season when Twilight becomes the new ruler of Equestria.