You misunderstand me; the inhabitants refer to it as a burned heron because they don't know any better. Obviously, their terminology is incorrect. They, by and large, don't know that. Since we've no elves, goblins or dwarves coexisting with the werewolves/wolfir, vampires, zombies, it doesn't seem likely that the greater populace would know what dragons are. The dragon is still a dragon; I'm providing an example of where Innistrad's dragons could come from. So that they fit in with the plane's theme. It's a canon plane, but this particular idea hasn't been discussed, so it's adrift upon the plane of Innistrad.
... WHY? Why wouldn't they know?
They know what a demon is, they know what a devil is, WHY WOULDN'T THEY KNOW WHAT A DRAGON IS?
Why does the absence of other things somehow make them incapable of understanding a dragon's basic premise? They don't need some bizarre origin.
And no, this is messing with a canon plane and canon ideas, so doesn't belong in the EM to start with. The purpose of this thread is to put random and incomplete ideas out into the aether so someone else can use it if they want to. That isn't what you're doing here. What you're doing is speculating.