There's a lake on the outskirts of the city. It's well stocked with fish, and there are plenty of plants that grow around the edges. Many a dragon has been lured there, only to meet their end at the hands of the one who lurks behind the waterfall.
However…there's also something within the lake itself. The water is deep and dark enough to hide many a large creature. There have been tales of individuals who've been fishing and seen strange lights down in the depths. Pale blue bioluminescent lights that seem to move of their own accord against the darkness. Or else they might flash, as if whatever is down there is communicating with something. Occasionally there could be eyes, or what might pass as eyes, peering through the murk towards the surface.
There have been stories of dragons coming to fish in the early morning/evening getting dragged into the water by something unseen. As they've tried to fight their way back up to the surface, the creature only drags them down deeper. Usually it would end with the individual never being seen again.
Usually.
It seems, though, that these individuals are being saved by a glowing blue…dragon/monster in the shape of a dragon? No one's entirely sure. Normally, all they see is a flash of pale fins, a glint of orange eyes and maybe the gleam of teeth before the…whatever it is shoots past to attack the beast that's got hold of them. Most of them agree that the second creature looks like an Imperial, but it's usually too fast to get a good look at it.
What is true, though, is that the survivors all agree that this being saved them. In the ensuing attack, the beast that caught them lets go, in order to defend itself, and they can then head up to the surface. Sometimes they get the feeling that they're being followed, as if something is making sure they don't get caught unawares again. Or maybe they'll catch a glimmer of bioluminescence from below, slowly circling beneath them. It usually vanishes as they reach the surface. Perhaps heading back to the depths, ready to protect the next unwary visitor that gets pulled from their boat.
