I would like to present a narrative about a medical and technical professional named Victor Amell. He is a lead engineer and tester for the recently renovated and rebranded NASA, which is currently engaged in a conflict with an alien race. The narrative requires the protagonists to relocate humans, with the setting shifted to the planet Kepler-452b. This planetary environment will feature the introduction of dragons and other creatures, though guidance is sought on the development of their species. For instance, the objective is to create a dragon with a more aerodynamic bone structure, enabling enhanced control and agility during flight.
Additionally, there are specials of dragons with more formidable jaws, reduced wingspans, and impressive terrestrial locomotion abilities. Lastly, the possibility exists for the inclusion of a system of miniature-breed dinosaurs and dragons as domesticated animals.
For more specific answers take a look at individual animals.
You could have dragons that glide with their skin flaps like flying squirrels instead of actually flying.
Burrowing dragons as I mentioned taking inspiration from the biology of badgers.
Dragons like tree frogs and chameleons with the ability to camouflage and have sticky pads on their feet.
Ice dragons with thick layers of fat. White scales for camouflage and countercurrent heat exchange system for the cold climate. Hey maybe you could have cuddling dragons.
I'd say have variations in sizes and environments. Some could reproduce like elephants and once in a long time and are going extinct. Others could be pests essentially. There is a lot of room for the differences you want.
With the whole alien element you could also add genetic influence. Maybe add genetic or tech enhancements that changed them.
From a world building perspective I'd suggest adding like evolutionary history. Maybe finding cave paintings or fossils.
Also there's a documentary I'd like to recommend called 'Alien Worlds' which explores how life would evolve on different planets and it would be VERY VERY useful to you I believe.