Dream-Snakes, and their greater (biologically or stature) cousin, FingerKings, are naturally found in Parabola, a dimension close to our own, but it is composed of Is-Not, a material that is the exact opposite of our material, and should not exist. It is not antimatter, just an analog to it. Anyways, if exposed to sunlight(the laws which dictate what is and what isn’t) it will probably burn, quickly, or just turn into ashes. I have come up with 2 relatively simple ways to use these properties to fight them, both involving the modification of bullets.
Bullet design #1: The Mirrorcatch Bullet. It is what it sounds like. If you do not know what Mirrorcatch Boxes are, I will explain. Mirrorcatch Boxes are boxes with mirrors on every interior surface, that will hold Sunlight, possibly because Parabola will keep out ANY sunlight. Upon impact of the bullet with anything of Is-Not, it will either burn a hole in what it hit, or disintegrate what it hits. Two flaws in this design is that a Dream-Snake with quick enough reflexes could escape through the dark mirrors to our world, or how you would obtain sunlight, even though the Travertine Spiral has a funicular, but information on it is almost as non-existent as that Dream-Snake I just shot. The next one has no flaws, other than being extremely dangerous to both parties.
Bullet Design #2: Correspondence Bullets. As with the previous design, this requires no explanation, unless you don’t know what it is. Correspondence is the language of law, sunlight in a letter form. You can learn it, and change the laws of physics using it. I don’t wish to do that, which will make it easy, and very dangerous. Correspondence causes what it is written on to heat up, but, since bullets are made of metal, we will not have a problem. I assume that it will be very easy to write what the physics currently are, but the stronger you make it, the more it can hurt you, unless you have not died, have not changed your position on the Chain, or turned into a monster. It’s all good if you have drank Hespidarian Cider, of course. When you shoot the Dream-Snake, it will either burn the area, turn it into a cinder, or disintegrate it, depending on how strong/if there were examples of Dream-Snakes being exposed to sunlight. Either way, the bullet will cut right through it. It will cut through the Is-Not air, the Is-Not trees, and the Is-Not ground, so recovery is not an option, unless it hits a mirror, and I do not know what will happen, then. With a bit more tinkering, you could make it resistant to gravity, and it would go on endlessly, and you could also fight off the Writhing River(River made of Dream-Snakes) with a submachine gun version of it. If mass-production is needed, bullets can be purchased by the bucketful, and Rattus Faber could be trained in carving a specific mix of Correspondence symbols on them. If you have made yourself an enemy of the forces these bullets function by, it could to be modified to work just behind mirrors, but there are some downsides to this. I have my suspicions that some/most snakes, like cats, have an avatar of a Dream-Snake, or are an avatar of a Dream-Snake. If not, then they are at least aware of the war between the Cats and FingerKings. You could kill snakes by the truckload if this is so. And if someone you know is possessed by a FingerKing, you could just shoot the person, and save them.
I hope you enjoyed the Correspondence Bullet that can kill evils, protect you from the Liberation, the only way to set up a Parabolan Base-Camp, and will be incredibly valuable to the cats, in their war against the FingerKings.