The dragon's strength is found in its tail, not in its teeth. Its lashing tail does great harm, and the dragon kills anything it catches in its coils. The dragon is the enemy of the elephant, and hides near paths where elephants walk so that it can catch them with its tail and kill them by suffocation. It is because of the threat of the dragon that elephants give birth in the water. The dragon's venom is harmless. The dragon has a crest and a small mouth. When the dragon is drawn from its hole into the air, it stirs up the air and makes it shine. Dragons are found in India and Ethiopia.

Dragons are afraid of the peridexion tree and stay out of its shadow, which will harm them. Doves roost in the tree to be safe from the dragon.

Dragons cannot stand the sweet smell breathed out by the panther and hide in a hole when the panther roars.

Thomas of Cantimpré adds two unusual stories: When a dragon is captured, men have themselves tied to its back and thus are carried quickly to far away places, but when they try to cross a wide sea the dragons tire and fall into the water. To destroy a dragon, a calf is killed and its belly is filled with quicklime (calcium oxide, highly reactive with water); when the dragon swallows the calf, the quicklime mixes with the moisture in the dragon's stomach to produce heat. When the dragon drinks water to cool the flames, it makes the quicklime react more strongly, producing more heat, and thus the dragon is destroyed.

Bartholomaeus Anglicus explains why dragons seem to breathe fire: Their venom is so hot that it sets the air on fire, so that it looks like the dragon is breathing fire from its mouth.

Albertus Magnus adds three serpents to the dragon genus: the ahedysymon, a dragon that bites out deep chunks of flesh; and the alhartraf and haudyon, whose bite induces a profound coldness. He also says the centipede is a kind of dragon.

The Devil is likened to a dragon because he is the worst of all serpents. As the dragon makes the air shine, so the Devil makes himself appear as the angel of light to deceive the foolish. The crest of the dragon represents the Devil crowned with pride. As the dragon's strength is not in its teeth but in its tail, the Devil, deprived of his strength, deceives with lies. The way in which the dragon attacks elephants represents the way the Devil attacks people, lying in wait along their path to heaven, wrapping them in his coils, and suffocating them with sin.

Dragons are often illustrated interacting with their enemies: Dragons menacing doves in a peridexion tree; a dragon suffocating a elephant with its coils, or threatening an elephant giving birth in water; a dragon hiding in a hole out of its fear of the panther; and dragons fighting with other animals. Dragons are not often shown breathing fire.

People frightened at night by ghosts and goblins and evil spirits can be freed from their terror by means of a medicine prepared from the tongue, eyes, gall, and intestines of a dragon. These parts are to be boiled in wine, cooled over night in the open air, and applied to the person morning and night.

Dragons have a translucent white stone called dracontites in their brains. The stone only becomes a valuable gem if it is cut from the brain of a living dragon; if the dragon dies before the stone is removed, it loses its hardness and dissolves. The dragon is put to sleep with herbs, then its head is cut off and the stone is extracted while the dragon's heart is still beating.

Dragons are edible but their flesh is very cold, and their gall must not be eaten.

Hildegard von Bingen says, "A person who has a stone in him should take some dragon blood and put it in a damp place so that it gets a bit moist. He should then place the blood in pure water for a short time, until the water takes some heat from it. Having removed the blood, he should drink a moderate amount of that water on an empty stomach. He should soon eat some food. He should do this with the blood and water for nine days, and the stone in him will be broken up by the strength of the blood, and he will be liberated. No one should eat or drink any of this blood pure and simple. If anyone were to do this, he would immediately die." (Throop translation)