Moon dragon
Moon dragons are the dragons found on the moonlet of the Discworld. All moon dragons are silvery in color, as is everything else—including the plants that the dragons eat—on the moon. Moon dragons have a sleek shape and flame backwards, using a rocket-like propulsion system in the low-gravity environment on the moon. They have nice wings, but these are used for steering the flight instead of gliding (as done by noble dragons) or flapping (as done by swamp dragons). Moon dragons are discovered when the crew of the Kite landed on the moon for refueling purposes, during an attempt to avert destruction of Dunmanifestin on Cori Celesti by the Silver Horde (see The Last Hero).
Opinion is divided among zoologists and students of these things, but following the discovery of the moon dragons, a theory was proposed that suggested that the whole sorry race of swamp dragons are the debased descendants of moon dragons who literally fell to earth. Separated from their high-octane diet of lunar vegetation, the dragons adapted to what they could find on the Disc, which neatly explains why they are such an unstable lifeform prone to so many illnesses and inadvertent explosions: they are doggedly holding on, living on a diet they were not originally meant to eat. Only the property of dragons, to internally rearrange themselves to make use of what poor-quality fuel there is, has ensured their survival as a species. Indeed, the ability of a dragon to rearrange its own innards to suit circumstances means that the swamp dragon has learnt to flame from what the human race has come to think of as the right end, but at the cost of losing much of its ability to fly. The recent existence of a mutant called Errol who was remarkable for (a) flaming from the "wrong" end and (b) being able to fly is now taken as supporting evidence for this notion: far from being a mutant or a sport, Errol was as near as possible a true genetic version of the moon dragon who thrived on the highly refined substances to be found in the Treacle Mine Road Watch House - ie, lamp-oil and Carrot's armour polish.
As Sybil Ramkin's expressed desire, on seeing Errol fly, was to breed back into the line to try to get more of this sub-species, it is highly possible that she and other members of the Cavern Club have managed to do it. After all, the Kite brought more moon dragons back to earth, and in one sense, it's hardly dragon magic, is it...
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More classic British children's TV... the Clangers[1] and the Soup Dragon...