Kurimus
I don't think that's a dragon. Maybe it was an eel that dreamed it was a dragon and thus accidentally became one. Mostly hangs around the ocean or beach, sometimes destroying ships or just creeping the crews out by following the ships and staring with it's eyes above the surface.

Atmos
The storm king, told to be born from the very first storm that ever stormed in the world. Spends all its time hiiiiigh above the clouds (as in stratosphere) and causes violent storms if it ever goes close to the ground. Generates electricity, and has grown so large that it's been theorized that it no longer has conscious mind or that it's so slow that humans can't comprehend it. It's actions are fast though, so in effect it's kinda like a more meaty and dense ball of storm.

Dracaver
It didn't always look like that. I mean it looked mostly like that, but its eyes were... less vertical. Herophilus was the air king, and the only fact case of getting killed and being bound to the land's former queen warrior, some hundred years back. Some time after that it died with its mistress, and forever since magicians have been wondering if it could be brought back, due to it still technically being immortal. Because you never know.

Nosphoros
The drake king. The sworn enemy of the king after it got betrayed and has sworn it would not die until all who crossed against it were dead. Got killed by Herophilus who (along his mistress) also died in the fight. Comes back as a zombie later.