Dragons in the Dungeons and Dragons role-playing games are the central monsters of the story. In our Eberron campaign they not only rule an entire mysterious continent, but they are credited with the very creation of the world and everything. Not only monsters, but also gods, is a pretty big order for a character to fill.
Skye, the Blue Dragon to the left above is a dragon who believes that human people are the most important part of fulfilling the Dragon Prophecy. Therefore the characters can rely on him as an ally, and sometimes even a patron. He is a blue chromatic dragon with lightning breath, and the Blue Dragon Aureon, his great great grandfather, is an important leader of the god-dragons worshiped as the Sovereign Host.
Phaeros, the great crested red dragon, is a servant of chaos who actively opposes all that is good. He works with orcish dictators and priests of the Dark Six to accomplish vast swaths of damage, destruction, and war.
He is a big bad villain that has to come at the end of a campaign, because dragons are not only powerful fire-breathers with monstrous monster-damage capability, they also know far more magic than even the wisest of wizards. My players have not crossed him yet, but if they start finding the missing dragon eggs, that will happen soon.
You may notice that my dragon pictures are mostly coloring-book pictures repeated with different colors, but in many ways dragons are like that. They all have the cookie-cutter qualities of a dragon, but with different-colored personalities and powers and ideas of good and evil.
Pennie is a copper dragon with divided loyalties and the soul of a clown. She never takes the adventure at hand too seriously. But if she decides to help the player characters find the missing dragon eggs, no ally will prove stronger and more helpful than her. And she knows things that the players need to learn from her to find the missing eggs.
So dragons come in many forms and personalities.
In fact, the search for the missing dragon eggs will be critically affected by the fact that the eggs have all five hatched and dragons instinctively protect themselves when young by using their polymorph self magic to become some other creature. And someone has implanted the idea of using human form as the default even though the wormlings have never actually seen a human being in real life.
So, playing games with dragons is fun and archetypal story-telling, and I will continue to do it, even if it means getting burned now and again.