The Skin Thing
Space colonists live in fear of a horrifying creature.
"The Skin Thing dragged itself along on two great stalks that looked like elbows. Imagine a person, out prone on the ground, that drags himself by fits and starts. The elbows strove to gouge the earth, as sharp and tall as circus poles, and they levered the body along by great drags. Its head stuck out eyeless, oblong as a horse’s. Behind the elbow-things it used to drag itself across the ground there stretched, like a laundry sheet strung out for drying, a tensile wall of thick pink skin."