Hollow Men

"It stood on the old stone wall. I could hear that sound coming from it now, maybe an engine of some kind. It was built like a dog, not like my dog, but some approximation of a dog. Except where the head should be there was just a blunt ending, a termination of the metal chassis that made up its body. On top, towards the front but in no way a "head", was a sort of octagonal protrusion. I could see it swivel, back and forth, then back again, pausing at times, spinning round, returning. I had no real idea if it'd seen me. But it raised one leg then the alternate, placing the rubber paws back down with disconcerting precision, with a springiness that vaguely appeared dog-like but was too sharp and truncated and powerful and unyielding. Tense metal, not flesh, the legs snapped rather than flexed."