This being St George's Day, I thought I'd have a look at dragons, and specifically at the key problems with dragons when it comes to fantasy literature.
They've obviously been a part of literature and consciousness for a long time. We have creatures of broadly that 'family' showing up in Ancient Greek myths (what is the hydra but a multiple choice dragon?) in Chinese and Northern European traditions, all sorts of different places.
Yet for the modern fantasy writer, they have a couple of small difficulties. They aren't humanoid. They're big. They're solitary. They're generally intelligent in a lot of cases. They're also immensely powerful, to the extent that if they're common, we have to ask the question of why humans are in charge and not them.
So, we have a creature that is hard to humanise on one level, because it can't fit into human cities, or relate to humans on a casual level. We have a creature that is also so powerful that it's a little unbalancing in many settings.
How can anyone possibly use one of those?
Well, obviously they have, using a number of pretty consistent strategies:
There's the strategy that has the dragon as a singular monster to be defeated. It's powerful, it's big. It's terrifying. But it's a monster. It's not really much of a character. It sits around on a pile of gold (because it's planning for its retirement, or just because it's a big, scaly magpie) and waits for heroes to come along and try to stab it. Occasionally, there are lots of them, but that doesn't change the part where it's just another sort of monster.
There's the strategy that has dragons as something to be tamed. Yes, they are powerful, but in this they are usually not also intelligent. So a great hero (or just a particular class of knight, depending on the series in question) may be able to prove their worth enough to control and use dragons.
Occasionally, we get the dragon as a mentor and/or manipulator. In this approach, it is intelligent, but its difficulties in fitting into a human society mean it is relegated to working through intermediaries, like the heroes. Exactly why it should care is often not established.