Alright, first let me get this straight, I am not suggesting the dragons the way you might think I am.
Right'O here goes.
A player travelling in the grey mountains or surrounding biomes on a very, very rare occasion could see the indistinct shape of a dragon flying on the far horizon. These would not be actual mobs, and would function similar to the sun or mist (much smaller) in that they're just part of the screen, and you can't actually get any closer to them.
Their purpose would be that of aesthetics and nothing more. Players could not interact with them in any way at all.
A number of people (Rayn, Alte, Madman, Warpig and myself to name a few) realized that this technique could be extended beyond dragons. Eagles, Fell Beasts, Flocks of birds (Crebain, gulls etc.), weather (Rainbows, Northern Lights), sandstorms, and even Santa's sleigh on Christmas are a few examples.
Well that's it. Thanks for reading and please tell me what you think.
Thread reopened: Endorsed suggestions can not be necroposted.