Wyvern

For tens of thousands of years, longer than anyone can remember, the cliffs around Flamekeep have been home to wyverns. Most of these are typical wyverns, generally Large and incapable of speech. However, these cliffs are also home to an exceptional strain of wyvern that is more intelligent and grows to much greater sizes.
Whilst they are still on average less intelligent than humans, these elder wyverns are capable of speech. The early settler of Daskara made peace with these elder wyverns, and many of Daskara's rulers had wyvern advisors on their staff. During the Year of Blood and Fire, when the overlord Bel Shalor broke free of it's bonds and subjugated Thrane, Tira Miron rallied the elder wyverns to her cause.
The wyvern Ashtarax carried Tira on their back during her final confrontation with the forces of the Shadow in the Flame. In the aftermath of Tira's sacrifice, the wyverns also adopted the faith of the Silver Flame and consider the protection of Flamekeep to be their sacred duty. They have relatively little concept of the wider Five Nations, and they don't care to learn. The wyverns serve the church because they believe that the church serves the Voice in the Flame, and they believe that Tira Miron still guides them.
Thrane fielded wyverns in battle during the war, which alone gave them aerial mastery only rivalled by Aundair, but they also had a few of these elder wyverns. These elder wyverns spread terror on the battlefield, they could carry entire squads into battle, and early in the war Thrane prioneered aerial combat techniques using them. Their trademark was the use of vast bags of holding which contained massive rocks and divine explosives which could be upended as the wyvern flew overhead.
Whilst the elder wyverns lack the power and magical affinity of true dragons, some of them have such deep faith in the Silver Flame that they can channel it's powers like any other cleric or paladin.