Princess Platinum

Princess Platinum is an Equestrian Unicorn and one of the many founders of Equestria. She was the leader of the unicorn tribe and the daughter of the Unicorn leader of the tribe, King Bullion. She was portrayed as considerably snobbish, viewing the other pony tribes as inferior to unicorns and treating Clover the Clever like a servant. Rarity plays her in the Hearth's Warming Eve pageant.

Role in the series
Princess Platinum, upon saving the three pony tribes from the Windigos' reign, referred to as the Windigo Ice Age, had treated Clover with newfound respect, and as a leader in respects to Starswirl the Bearded for making her grow up into a wise pony. She also wielded one of the Elements of Harmony alongside Clover's other friends long before the birth of Princess Celestia and Luna. But though they were specified dead, the group was actually imprisoned in a village nearby the hometown of Stygian thanks to the fearmongering ancestors of Bishop Dipper, and remain here to this very day, and have yet to be released.