A dragon of the Wyrmberg mentioned in The Colour of Magic. The dragon rider K!sdra rode this dragon, and together they hunted down the Wizard Rincewind. Despite Bronze Psepha's best efforts, after K!sdra was knocked out, Rincewind threatened to kill him if Psepha attempted to singe him, and the dragon stood down. Rincewind and K!sdra then rode Psepha back to the Wyrmberg.
Like all the dragons of the Wyrmberg, they only appeared if someone truly believed in Noble dragons, and even then, the believer had to be in an intense magical field, powerful enough to pull a dragon into the world. So, if Psepha left the magical field of the Wyrmberg, he would get more and more transparent, and then vanish.