When he arrived at a clearing, he saw a dragon holding a lion by the tail and burning its flanks with its flaming breath. My lord Yvain did not waste time observing this marvel. He asked himself which of the two he would help. Then he determined that he would take the lion’s part, since a venomous and wicked creature deserves only harm: the dragon was venomous, and fire leapt from its mouth because it was so full of wickedness.

Chr├ętien de Troyes
https://coldewey.cc/2013/07/when-he-arrived-at-a-clearing-he-saw-a-dragon/ ┬╗