Drakhrun

Drakhrun appears to have became a Throne World relatively recently. As a result, the influence of the Dark Lord didn't make it lose all of its connection with what can be considered the 'sane' rules of the Vassal Worlds. To begin with, Drakhrun is a spherical world of limited size (although it's already several times larger than Earth), which cycles around a star. However, this is pretty much where sanity ends.   Drakhrun and (if Dominion's research missions are to be believed) all other worlds of that star systems are composed of incredibly dense concentrations of dead dragon-like creatures (it's said 'dragon-like', because some of the shapes are harder to categorize, due to time grinding them badly). Some of the half-crushed skeletons forming the core of Drakhrun-the-planet are estimated to approach 50 000km in length. The skeletons start merely fifty meters under the ground, with only a brief sedimentary layer of stone and soil above them.   Surface is covered in skeletons too. While significantly smaller, there are still there - and some of them are large enough to have entire settlements carved in their exposed ribs. The creatures behind all those corpses are largely unsure. There are similarities between them and the strongest of the servitors following Ancalagon (and the First Dragon himself too) - however these creatures are known for their 'look' to be the result of human minds creating a crude approximation of what they see. If anything, the part where the skeletons resemble dragons so much is considered slightly unnerving by many scholars.