To create the dragon fire, the FX team used a pair of military-style flamethrowers.
The entire movie was filmed in natural light.
The dragon in the movie actually has a name, called by its full name by the sorcerer Ulrich, and by its first name by King Casiodorus Rex and by Galen: Vermithrax Pejorative.
First film to use go-motion, a variant of stop-motion animation in which parts of the model (in this case, the dragon) were mechanized and the movement programmed by computer. During shooting, the computer moves the model while the camera is shooting, resulting in motion blur, which makes the animation more convincing.
Filmed as a co-production between Walt Disney Pictures and Paramount. A rare co-venture between the two. Perhaps because of Paramount's influence, Dragonslayer (1981) was more mature and realistic than most Disney films of the time. Characters die and we even get some brief nudity. Things that were rather controversial for a Disney film of 1981 and even more so today. It may have accounted for why the film was a box-office failure.
Its almost an hour into the film before the dragon makes a proper appearance, and then an additional 20 minutes after that before we see it up close.
When we hear a bell chime, it sounds exactly like the gongs heard on Big Ben.
Galen is referred to as a sorcerer's apprentice at one point. Which is probably Disney making an in-joke to the classic Mickey Mouse short.
Peter MacNicol's film debut.
Shot on location in Wales. But the final scene was shot in Skye, Scotland.
Including the hydraulic 40 foot model, 16 dragon puppets were used for the role of Vermithrax, each one made for flying, crawling and breathing fire.
The story has many familiar dragon motifs found throughout Western culture. In particular Saint George and the Dragon, in which maiden sacrifices were made to appease a harassing dragon. Saint George's tale also includes a sacrificial lottery resulting in the surprise condemnation of a princess. Saint George is also frequently depicted with a magic (blessed) lance or a sword.
Many town locals were employed in the film as village extras.