Kairothrax

Kairothrax was a silver dragon from the Iron Crags. When the Iceblood clan of frost giants slew his mother, they took Kairothrax prisoner to use as a mount. He was rescued by the Challengers of the Unspeakable, and thereafter elected to serve as a mount for the dragonborn Elytra, impressed by her single-minded desire to battle the threat of the Far Realm. His time with her was short-lived, however, as he was utterly destroyed when the group battled a living sphere of annihilation within an ancient Estorian vault.