...what, 2 female spiders? 2 carnivorous maggots? Hell, how about a human-sized carnivorous millipede-crossed-with-a-praying-mantis-and-orb-spider.
I admit some of the horror of the story was taken away, through no fault of the author, because I spent most of it trying to figure out what the hell the protagonist was under his skin. At first I thought a giant
velvet worm, given the apparent 'muscle' strength and the mouth shape, but velvet worms are predatory and don't have armor. I think millipede is probably closer. If there IS any real world analogue, of course.