D&D Monsters: Lamias

The lamia is another creature originating in Greek myth. However, the route from the myth to the RPG monster is rather more circuitous than is the case for, say, centaurs. In the original myth, Lamia is an otherwise normal woman cursed by the gods into becoming a child-eating cannibal and hence, a sort of bogeyman figure. By Roman times this has shifted to the point that lamias are a race, and the stories around them more closely resemble those of the succubus than of ogres.

At some point between then and medieval times, lamias change again, keeping their powers of sinful seduction, but now becoming part-serpent - physically resembling the yuan-ti of D&D. In fact, outside of gaming, this may remain the most common depiction. In the 17th century, however, an alternative description made them quadrupedal, a scaly hooved creature with a woman's head and breasts. This, combined with a desexualised version of the seduction powers, seems to be the likely inspiration for the game version.

D&D Monsters: Dragon Turtles

Dragon turtles have their origin in Chinese mythology, combining the power of two of the four "auspicious beasts" to bring together their positive aspects. As such, while they don't make direct appearances in mythic tales, they are apparently common in artwork and statuary due to their supposed positive effect on feng shui. Having said which, the version that appears in D&D, while doubtless inspired by the mythic creature, also has features in common with the European conception of dragons and certainly doesn't seem much like a feng shui ornament.

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1E

The 1E version of the dragon turtle, so far as we can tell, has much in common with traditional depictions of the creature. It has a turtle-like shell and a long, thick neck that probably doesn't retract inside (as, indeed, is the case for some real-world turtles). The head is clearly draconic, with a snout and fangs rather than the toothless beak of turtles, and a pair of feelers or decorative tufts on the forehead. Significantly, it also has the prominent dorsal crest seen on many D&D dragons. We can't see the limbs in the illustration, but we're told that they have claws - something true of most real-world turtles although, as it happens, not of the deep sea sort, which have flippers.

D&D Monsters: Metallic Dragons

In European myth, dragons are almost universally regarded as evil - rapacious monsters that lay waste to the countryside, have to be slain by heroic knights and, in many cases, essentially breathe hellfire. They are, sometimes literally, diabolic creatures. The same is not necessarily true in other cultures, such as that of China, where dragons may not necessarily be easy to parlay with or recruit as allies, but aren't fundamentally hostile, either.

In D&D, the good counterparts to the evil chromatic dragons are, of course, the metallic ones. Indeed, they are among a relatively small number of 'good monsters' to make it consistently through into the core books of later editions. Up until 5E, they are portrayed as rarer, but individually more powerful than, the chromatic dragons. They are perhaps even rarer in games than they are usually described as being in the universe (in two campaigns of Critical Role, the PCs have so far encountered at least seven chromatic dragons, and only one metallic). Doubtless, this is because they are less useful in a typical game if you're not going to fight them - and they're too powerful to be regular allies.

D&D Monsters: Blue Dragons

A considerable number of mythological deities are said to throw thunderbolts - Zeus and Thor are merely the most familiar of these to Europeans, with examples known from many other cultures. Actual mythic creatures that throw lightning, however, are much less common, although Chinese dragons are at least associated with thunder and storms. In D&D, however, it seems an obvious attack mode once we've dealt with fire and ice, and, naturally enough, it's associated with the dragon that's the colour of the sky.

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1E

The original picture of the blue dragon shows an animal with a moderately long and heavy snout, large eyes, and elongated canine teeth. More distinctive features include the fact that the dorsal frill of the green and black dragons is here replaced with a series of large triangular plates, which may be projections from the vertebrae, but could be separate structures similar to those on a Stegosaurus. The latter possibility is supported by the existence of three similar plates on the forehead. In front of these, there is a row of four  bony spikes, one of which is enlarged to form a narrow nasal horn. As usual, this doesn't look like it would be of much use in combat, at least compared to the teeth and claws, so it might be a display structure.

D&D Monsters: White Dragons

While witches, evil sorcerers, and the like, may create freezing cold storms, beings that attack by virtue of simply being very cold are not common in myth, or indeed, in early fantasy literature. Tolkien mentions "cold drakes", but these are simply dragons that don't breathe fire, rather than being any supernaturally low temperature. Nonetheless, when Gygax was looking around for different attacks for the five basic chromatic dragons, intense cold seems (at least in retrospect) an obvious fit. Perhaps as a counterpoint to the fiery dragons being the most powerful these, the white dragons, became the weakest.

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1E

White dragons are not only the weakest of the chromatic dragons but the weakest of dragons overall. A step down from the black dragons, while they do have much thicker hides and stronger jaws, 1E white dragons have about the same ability to sustain physical injury as a tiger. In fact, their claws do less damage than a tiger's do, so it's possible that their legs are actually less muscular (or the claws are blunter, or smaller, which seems unlikely).

D&D Monsters: Red Dragons

Many medieval descriptions of dragons make no mention of them breathing fire, and this does not seem to be part of the original myths of the creatures. Nonetheless, the idea that dragons breathe flame does seem to have originated in medieval Europe, and is now de rigueur in fantasy depictions. It probably arose because of the association of evil dragons with hellfire, and the general idea of fire-breathing creatures certainly predates it (Leviathan breathes fire in The Book of Job, for example). 

In D&D, of course, it was originally decided that the five types of chromatic dragon should be distinguished by each having a unique attack, so that green dragons breathe poison, black dragons acid, and so on. Naturally, the most powerful of all the chromatic dragons was going to be the one that breathed fire, fitting the legends on which the broader idea is based.

D&D Monsters: Green Dragons

Medieval descriptions of dragons imply that they look rather like snakes, but they were said not to be venomous and, since they weren't always fire-breathing either, were often just very very strong. Some medieval bestiaries, for instance, describe dragons killing elephants by wrapping them up in their tail and squeezing like a constrictor. The poisonous counterpart of the dragon in medieval lore is the basilisk - which is basically just an incredibly deadly snake, much like the version in The Philosopher's Stone.

In D&D, the basilisk is quite a different creature, and very far from being legless. While the association of poison with serpentine beings make sense, it's not common in depictions of dragons. The D&D idea of certain dragons belching poisonous gas instead of something flammable is likely an original one - something added so that each of the five chromatic dragons had a unique attack mode. And in this case, of course, that's the green dragon, the mid-point in the five-point scale of increasing chromatic dragon power.