Bivotar and Juranda before Leblong.
Dragons are monsters, large, winged reptiles that breathe out fire and smoke. Although quite intelligent, dragons are also notoriously naive.
Apparently fairly common in the old days, the species encountered a little problem in the form of Dimwit Flathead, who took it into his head to hold a feast on the meat of 300 slaughtered dragons.
Dragon eggs were also another delicacy, as King Syovar also had them for breakfast.
The twin dragons Leblong and Berlong had a feud. Grawl made a bargain with Leblong promising to kill Berlong, and Leblong agreed to guard a tunnel in the Cavern of Doom for 1000 years. Bivotar and Juranda fooled him by showing him his own reflection, taking advantage of the dragon's naivete.
The dragon found by the Second Dungeon Master also died when it was startled by its own reflection.
The Legend of Wishbringer, tells of Thermofax that had an appetite for careless knights.