In chapter 14 of an apocryphal Jewish text accepted as Holy scripture by some believers, we can read the story of Daniel and the Dragon.
The Babylonians of that time worshiped a sacred dragon named Bel-Marduk. After Daniel exposed the fraud of the priests about the idol of Bel and showing that it was not alive, King Cyrus asked Daniel to worship the dragon god Bel-Marduk. This god is surely alive, he said. Unlike Bel who was an idol of bronze and clay, the dragon was a living being. It was for the Babylonians an immortal god. Daniel asked the king for permission to kill the dragon without using a sword or a club to show him that he is not wise to worship a mere mortal animal. Daniel proved to the king that the dragon was not an immortal god by making a cake with pitch, fat and hairs which he gave to eat to the dragon. After ingesting the indigestible mixture, the animal exploded.
If we look at this text literally, the dragon is described as a simple beast that can be easily killed. The dragon of the text seems to have a digestive system capable of producing a lot of gas. That sounds like the bloat in the ruminants. When a cow eats fermented foods that do not suit it, the rumen (part of the digestive system) can produce a huge amount of gas. If no Intervention is made to withdraw this gas, it may die and explode.
Perhaps this gives us a clue that would allow us to identify what kind of animal the author was referring to and learn more about the mysterious dragons. The mystery remains.