A dangerous, alien plane where glowing frog-slimes slither and slurp, metal-skinned bird people rebuff diplomacy, and only the endless subterranean tunnels are safe (just mind the gravity-bending moles). Visitors will have to skulk around in the dark to avoid the curse carried by the sunlight. Because (have I mentioned?) the sun is the source of a powerful curse--one that covers the whole planet.
"It is said that among those people they have a loathsome custom- that they keep a spotted dog always waiting beside the gate of the yard where they bury the dead, and that in every funeral they allow this spotted dog to feast upon the dead, so that it grows fat and wise with the knowledge of the dead... Many necromancers do seek out these spotted dogs, and ask of them sciomantic knowledge, or take them as familiars." -Author unknown, "The Ways of the Necromancers"