THE SCENE: In Geoffrey of Monmouth’s translation of the prophesies of Merlin, a scene of vicious dragon-on-dragon combat is finally resolved when one naked dragon starts climbing on the backs of the other dragons.
THE TEXT: The Dragons will attack each other and tear each other to pieces. A Dragon with wings will overwhelm a Dragon without wings, driving its venomous claws into the other’s muzzle. Two more Dragons will join the battle and the one will kill the other. A fifth Dragon will replace the two dead ones and will destroy the two left alive by various stratagems. It will climb on the back of one, holding a sword in its claws, and hack its head away from its body. Then it will cast its slough and climb on the second one and seize its opponent’s tail in its right and left claws. Naked it will overwhelm the other, when fully covered it will achieve nothing. It will torment other Dragons by climbing on their backs, and drive them round the kingdom.
– Geoffrey of Monmouth, The History of the Kings of Britain, 12th Century AD