The land beyond the silvered sheen of mirrors in terrible, sharp, and irrevocably hostile to us. Razor-limbed stilt-people stride through forests of cutting edges and jagged points. Fractal-plane mountains stab up from the horizon, and a cold and silver sun looms above in a sky filled with clouds of metal-dust. There are soft and blunted forms in that world, but they are a hazard to its inhabitants, so they do away with as many as they can. If they could see our world, they would despise it and us, a world of crushing death.
Thus, it is not idly that people warn of the long years of ill-fortune that follows the shattering of a mirror, though they do not know the full truth of it. Sometimes when mirrors break, some being from the scalpel-world might slip through, unclad in physical form except for the dagger-splinters of glass from the broken mirror.
It looks something like a swarm of bees imitating the shape of a dog, if the dog was something like a porcupine, and the bees something like bayonets.
The size of the Skiver Hound depends not on the size of the scalpel-being that made it, but thankfully on the size of the mirror that forms it now. Hand mirrors create only kitten sized hounds, easily bludgeoned to nothing. Full-length body mirrors however will form hounds the size of hunched over people. As far as is known, there is no upper limit to the size of a Skiver Hound, it is limited only by the size of the broken mirror.
They behave somewhat like a rabid ape that has been force-fed bath salts. They rage uncontrollably, shredding and slicing, ruining and destroying. When a Skiver Hound is born, the nearby area is rarely well defended enough to contain the hound, let alone survive it. Once the immediate area is cleansed of the obscene, blunt meat-things the hound begins to shape the world to its liking. Grinding down curves to flat planes, sharpening points, polishing what it can to mirror-sheen. A further result of this is the entry of yet more scalpel-world beings to this realm. Rather than life begetting a habitat, the habitat of the scalpel-world begets life. A mature Skiver Hound’s lair is a razored nightmare, all sharp points and whirling splinter-creatures.
Even when a Skiver Hound has fully transformed its lair, it will not stop. It merely starts the process over.
And it’s a notoriously hard cycle to break. Trying to fight a Skiver Hound is like fighting the wind, weapons and spells pass through the vacant spaces, and even when they do connect, the splinters of glass merely split into smaller splinters. In return, the Hound will scythe through you, the shards slicing and cutting and stabbing as the beast rams into and through you. Eventually though, the Skiver Hound degenerates into a whirling, furious cloud of sand, and the threat is done, mostly.
The only way to fully destroy a Skiver Hound is to melt the glass that forms its presence in the world. Binding the glass together smothers the force inside, finally fully exposing the scalpel-beast to our existence enough to smother it. Of course, forcing an angry swarm of glass shards into the flames is not such an easy task.
If a Skiver Hound can be slain and its glass recovered, it can be used to form the basis of rather potent divination tools, though one must always be careful never to break them. These recovered glass tools could also theoretically be used to access the Scalpel-world the Skiver Hound originated in. This is uttermost foolishness, needless to say.
One thing a Skiver Hound must never be exposed to is its own reflection. By forming a reflection of it, another will be born within the mirror. The reflection-beast will rage and batter against the inside of the mirror until eventually it breaks, and another Skiver Hound is loose upon the world. One way to deal with a Skiver Hound, even if only by a loose definition, is to lead a Hound to a reflecting pool. The Hound, in an attempt to bring forth its brethren into the world, will stare fruitlessly into the depths of the pool. A hound will be born within the water’s surface, but it will never be able to escape, and the two will be transfixed upon the other until something distracts the real one.
A Hound born in a mirror that it cannot break, however, will never leave the mirror, and no known force can exorcise it. This wouldn’t be such a problem save that such a mirror must be protected against breaking lest another hound be born, and that the hound-in-the-mirror can harm creature’s who’s reflection can be seen in the mirror, wounds manifesting on the real creature as the mirror-thing savages the reflected person.