Slay the Dragon is the second part of the 26th episode, and the final episode of the series. It was preceded by Quest to Success.
Circus wagons go by Camelhot, and King Allfire goes to the circus, since his old chum Stu joined the circus. Shortly after, Flicker reads a flyer that says "Slay the Dragon for 50 gold coins". So he, Sir Loungelot, Sir Blaze, and Sir Burnevere go to the circus to save Allfire.
First they try disguising themselves as clowns, but the ringmaster catches them, telling them that they're late and making them ride a unicycle (Loungelot going on top despite Flicker's insistence that the lightest dragons should be on top). When they see Allfire waving Excaliburn around at the top of the bleachers, as if in a battle, they crash the unicycle.
Next they disguise themselves as trapeze artists, but the ringmaster puts them to work as well. At the top of the trapeze tent, they see Allfire being chased by serfs, and swing down on a trapeze to rescue him, with a plan ending with Flicker riding an elephant. The plan backfires, as the elephant runs around randomly, and when a bird pecks at Loungelot's feet, he, Burnevere, and Blaze fall, Loungelot tearing down the tent in the process.
Next Flicker, Burnevere, and Blaze disguise themselves as tigers with Loungelot as a ringmaster. However, as Loungelot enters the ring, the ringmaster locks Flicker, Burnevere, and Blaze in a cage with other tigers, while three real tigers enter the ring. Loungelot mistakes them for Flicker, Blaze, and Burnevere until he sees King Allfire, by which point Flicker, Blaze, and Burnevere arrive, and the tigers attack Loungelot. Serfs take Allfire to the Slay the Dragon tent.
Inside the Slay the Dragon tent, the executioner asks for a volunteer, and Allfire volunteers. He is put onto a rotating wheel with the executioner about to throw a knife, when Flicker and the dragon knights run onto the stage to stop him. He pulls off his mask to reveal that he is a dragon, and that he is Stu. His full name is Stupendous Slay, the knife-throwing act for the circus. The "Slay" in Slay the Dragon was referring to him, and the flyer was to advertise his knife-throwing performance, which was intended to not hit the target on the wheel.
Allfire tells the knights about his day in the circus, revealing that he was swinging Excaliburn around to entertain kids due to the clown being late, and that the serfs weren't chasing him, but rather he was chasing a monkey who stole his peanuts. After Allfire finishes telling his story, the angry ringmaster enters and chases Loungelot into the distance for ruining his tiger show.
- When Burnevere suggests that they fly, Flicker says if they expose their wings, their identies as dragons will be revealed. However, their wings and tails are clearly visible.
- Final appearance of Flicker, Loungelot, Burnevere, Blaze, King Allfire, and Cinder and Clinker.