Kazuuldruuk the Scourge of Calcibur
A male mature adult green dragon (753 years old) from Calcibur. He was brought to Alech'nor from his planet through a Holman Conduit by Lord Xy, similarly to hundreds of others from many other planets. They were told that this continent, barred to dragons for 6000 years, held fantastic amounts of treasure, enough for all of them, once they worked together to crush its humanoids.
This they did, but the treasure was not shared equally, with many excuses made as to why not. Kazuuldruuk was one of the earliest to grow discontent with this, joined in secret by a few other green dragons, who incidentally were the most common kind of dragon to answer Xy's call. He went looking for the truth behind Xy's efforts, finding it from Falben Farwalker. Incensed about being lied to and used to settle a personal affair, the dragon conspired with the heroes against Xy, telling them exactly where they could find their friends and their condition, further promising to work to undermine At from within.
He accompanied the party into the Dragon Halls, went with them through the time distortion, and was left by them 6000 years in the past.