A surgeon’s coat hangs neat over a body that won’t hold its own shape. Purple flesh bulges through seams, sprouting slick tendrils that curl around boots and belt like impatient fingers. One hand has become a many-jointed claw, glossy and wet. Where a face should be, folds of meat and writhing filaments knot around a single staring eye and a split grin. He lifts a bone-saw with practiced calm, and the air smells of antiseptic fighting rot.
Alien parasitic worms that infest the brains of Humanoid bodies mutate their hosts into wormhost surgeons. These aberrant husks are obsessed with anatomical study and with finding new Humanoids to infest with larval worm slurry to propagate their kind. They can pass for ordinary people in most cases but must take care to hide their exposed brains and the wriggling worms within their flesh.
Wormhost surgeons are drawn to seek out and infest sapient victims, so intelligent creatures with veiled minds slip beneath the surgeons’ notice.