This is a "Seeker" - a genetically created hunter designed to sniff out menstruating women and disable them until they can be captured for the breeding programs of the United Militias of the Crystal Cross. Women who cannot be so used are turned into Seekers and other monstrosities.

...Now I was being hunted. Then I heard them, the characteristic hissing and clanking and high pitched keening which was their method of communication. I guessed them to be about three or four hundred yards down the mountainside, closing rapidly. I controlled my breathing and began silencing my mind; Seekers too have rudimentary mind communication abilities, probably because their minds were once human.

Then I saw them.

The slope where I was hiding was pretty steep, and heavily forested, about a thousand feet below the tree line. Directly below me, the slope was flat and bare for about a hundred yards, a sort of shoulder of rock that supported only a few low plants. Past that, the open floor of the forest was visible for another hundred yards or so.

As I watched and performed my ritual for silencing thoughts and fears, the first of them came into view. If you are reading this, you've probably never seen a Seeker, so I'll do my best to describe them. Seekers were modeled after spiders, but instead of eight legs they had only six. They had big bulbous bodies, and the legs came out from underneath the middle. The legs were jointed like spiders, and long; metal legs with hydraulic tubes and mechanical segments. The bodies were about four feet long and when traveling stood about eight feet tall, but they could extend upward on those legs as high as twenty feet. At the front of the body, two mechanical arms extended forward. They didn't have hands, exactly, more like pincers, with an inner hand that had, among other things, an extending needle for injecting poison or paralyzing agent in their targets. They also had what amounted to guns, and these could shoot either projectiles which were sometimes explosive, or a sticky web like substance to trap their prey. Between these arms was a head. A human, female head, but with six specialized eyes and an exagerrated four segment nose. No mouth; instead of a mouth they had a curled proboscis like a mosquito. They used it the same way a mosquito did, for the same reason. They were blood suckers. The body was a blotchy, black or dark gray chitinous substance, very thick and hard, like armor.

They were totally repulsive, something out of a Heironymous Bosch nightmare, and they smelled like a gangrenous wound. We never found out exactly how they were made or even how they worked. Every time we cornered or trapped one, they would dissolve into a toxic mess, even the metal parts. We think it was some gengineered symbiont bacteria or microbe that was part of their chemistry, triggered by death, incapacity or capture to destroy its host.

Below me in the forest were three of the things, scuttling about, sniffing the ground and the air, keening to each other like wailing women at a massacre.