Tekthyrios

Tekthyrios was a storm dragon living in a temple on Celestia.

History
A portal was located in Tekthyrios's belly that was connected to the inside of a snake in the City of Brass in the Elemental Plane of Fire. When the alu-fiend Aliisza activated the portal by feeding Tekthyrios mushrooms, Zasian Menz and Kaanyr Vhok were able to enter Celestia from the City of Brass, though in the journey they lost 12 years. Zasian then possessed the dragon. / The draconic hobgoblin Myshik Morueme followed Zasian and Vhok, and, once emerging from the dragon's maw, allied with the storm dragon, not realizing it was being possessed by Zasian.

Novels

 * The Gossamer Plain (unnamed)
 * The Fractured Sky