Atropus

Atropus, known as the World Born Dead, is an undead planetoid whose coming is a harbinger of death and destruction.

Once a great power, little remains of Atropus but a decaying, disembodied head the size of a small moon (700 miles in diameter), apparently made of black stone, heavily cratered, and covered with foul amniotic fluid. It is barren and rocky, roughly spherical and with mountainous ridges, deep trenches, and sharp spikes upthrusting from the ground. Noxious tar bubbles up from the craters. Glossy black stones each 40 miles in diameter form its eyes. The atropals—stillborn gods—are said to be cast-off detritus from Atropus's substance. Undead conjured from nightmares also inhabit the world, and the master of them all is a headless, alien humanoid that is the focus of Atropus's incomprehensible intellect.