The Night Land features a far future landscape, where the sun has gone out, which is made treacherous by the presence of various non-human "forces" and "powers", and monstrous creatures waiting to attack the unwary traveler.
Of course, William Hodgson didn't know about nuclear fusion or stellar evolution--and really, a future Earth orbiting a dead sun would be orbiting a white dwarf, with a surface temperature somewhere around 40-50K. Rather chilly to support creatures based on contemporary biology.
But suppose something evolved to live there and threaten spacesuited travelers walking the surface. How might such creatures function and survive? (If necessary, assume that sometime in the preceding billion years, humans found it convenient to do some biological engineering and introduce artificial lifeforms that could survive on the cold Earth, which have since evolved out of control; they do not need to be based on carbon and/or water.)
- The atmosphere of the dead-sun Earth is very thin, and composed on hydrogen, helium, and neon.
- Water, oxygen, nitrogen, and carbon dioxide are common surface minerals.
- Illumination from the white dwarf sun is about 1/1000th of what the contemporary Earth receives--so full sun at noon is still 400 times brighter than a contemporary full moon. Plenty bright enough to see by, and to support (slow) photosynthesis.
- Some creatures must be mobile, but need not be extremely active; if an individual can chase down a lone human in a burst of energy once every thousand years, that's just fine.
This question is part of the Anatomically Correct Series.