Fantastic Beasts and Where to Find Them gives some basic information on the types of dragons and their behaviour, but little about the structure of the dragons themselves. I am referring to the question of limbs, which isn't made clear in the books.

So, how many limbs do dragons have? Four or six?

A dragon with six limbs would probably look like what people typically think of when they think of a dragon - a sort of big lizard with wings poking out of its back. However, this is anatomically impossible, and there is no such thing as a six-limbed vertebrate in nature (save for mutated Chernobyl frogs!). However, in the Harry Potter world, there are animals like Hippogriffs and Threstrals, which do have six limbs (four legs and two wings).

On the other hand, a dragon with four limbs would be more like a reptilian bat, with the arms forming the wings. The arms might have one or two claws, but most of its fingers are long and thing to form the framework of the wing. This four-limbed dragon is much more plausible in real-world terms, and the Hungarian Horntail in the Goblet of Fire movie is portrayed like this.

Now, how many limbs do you think dragons would have? Or could some species of dragon have four limbs, while others have six?

Here's another question that I've been pondering:

How do Chinese dragons fly?

European-style dragons traditionally have wings growing from the back, but I have yet to see any depiction of a Chinese dragon with any kind of wings at all. Furthermore, Chinese dragons are built more like snakes, but just with legs. However, many seem to be able to fly without wings, because the dragon is a magical and powerful animal.

In the world of Harry Potter, there is only one species of Chinese dragon, the Chinese Fireball, also called the Liondragon. So, how do you think Chinese dragons fly, if at all? Could the Fireball be the only flightless dragon? Or do these species actually have wings, despite every depiction of them that suggests otherwise? And if the Chinese Fireball does have wings, then does it have four limbs or six?

How do you think Dragons breath fire?

Is the fire generated magically, or is it the process of some chemical reaction? Furthermore, do dragons only shoot mere flames, or can they shoot something like napalm, which would be much more effective?

And now for some more mundane questions...

How many eggs do you think dragons lay at a time, and how often?
What roles do male and female dragons play in the raising of young?
What is the average dragon lifespan, and how quickly do dragons grow?

Anyway, those are some of my thoughts/questions about dragons in the Harry Potter universe, and I'd love to hear your comments and answers.

Tim the Enchanter