I know of a few. I know there's the Ancient White Wyrm, Ancient Sand Dragon, Ancient Emerald, and Ancient Crimson, and Ancient Hiryu. Does anyone know of other Ancient Dragons? (Non-rare please.) Trying to make a list of them for something. :)
Ancient forest guardians and also the dragons that spawn with treasure map chest if you want to count those. I think there is also some weird little creature in Ilshenar which name I can't remember, but it looks like a Hiryu if I remember right which I don't consider as dragons really though anyway.
Cool. Hiryus are dragons though. :p They're vulnerable to the Dragon Slayer mod. ^_^