Ymir Fritz is a legendary figure in Shingeki no Kyojin, known as the original source of the Titan power. She was a slave girl who gained the power of the Titans after making contact with a mysterious entity, becoming the first Titan and the ancestor of all Subjects of Ymir. Her existence is central to the series’ mythology, history, and the origin of the Eldian empire. Ymir’s legacy shapes the conflict, the Titan curse, and the fate of every Titan shifter.