|Books||The Colour of Magic|
K!sdra was a dragon rider of the Wyrmberg. He rode the dragon Bronze Psepha, at least, he did whenever he was close enough to the magical field surrounding the Wyrmberg that allowed dragons to exist there. Whether he was a magic-user, or someone with the Power to summon dragons, or just someone who rode a dragon summoned by someone else, is unknown.
He was one of several riders dispatched by Liessa to capture Hrun the Barbarian, Twoflower, and Rincewind, who had entered the Wyrmberg's magical field by accident and were now attempting to escape. He went after Rincewind, who had managed to evade the first wave that captured Hrun and Twoflower. Normally, capturing Rincewind would have been no trouble at all, but in this case, Rincewind was wielding the sentient sword Kring, which curved up and caught K!sdra's blade, sending both it and him flying. Rincewind then took K!sdra prisoner, and had him fly Rincewind up to the Wyrmberg to try and rescue his companions. He only did this because Kring was attempting to kill K!sdra (not just hold him at throatpoint).
When they arrived at the Wyrmberg, however, other dragons and guards armed with crossbows cornered them, and K!sdra gained his freedom, ordering Rincewind to surrender (which he did not do). He then helped Rincewind into a pair of hookboots for a duel with Lio!rt Dragonlord. Nothing was mentioned of him after this.