Ratatoskr (Final Fantasy XIV)

Ratatoskr was a great wyrm in Final Fantasy XIV, one of the First Brood. One of the seven wyrms born of Midgardsormr, she was slain a thousand years ago.

Story
Early in the Sixth Astral Era, several tribes who followed Halone arrived in Coerthas in search of "The Promised Land." Being the dominion of dragons, they feuded with the natives until Saint Shiva's love for Hraesvelgr inspired a time of peace.

This would not last: a few centuries later, King Thordan coveted the power of the great wyrm's eyes, and with his Twelve Knights, betrayed and murdered Ratatoskr. They took her eyes and consumed her, gaining the tremendous power from it. Her brood-brother Nidhogg, discovered the deed and furious attacked them. While Thordan and four of the knights were slain, Nidhogg's eyes were gouged out. Consumed with wrath, the blinded great wyrm told Hraesvelgr of the treachery and demanded an eye after what his peace had wrought.

For the next one thousand years, Nidhogg would pursue a campaign of vengeance against the descendants of Thordan and his Twelve Knights, the Holy See of Ishgard. As many Ishgardian citizens, even lowborn ones, were ultimately descended from one of the Twelve Knights, an element of Ratatoskr's power could be activated by dragon's blood. Many heretics opposed to Holy See doctrine would consume dragonsblood to transform into humanoid dragons such as aevis, syrictae, or diresaurs and side with the Dravanian Horde.