Free The Shadowhunter's Codex by Cassandra Clare, Joshua Lewis Page B

black body with a long domed skull like an alligator’s. Unlike on an alligator, its eyes are in an insectile cluster on the top of its head. It has a vicious, barbed whip tail and a thick, flat snout. Raveners possess sharp fanged teeth, which envenomate their prey with a deadly toxin. In time the poison will burn away all of the life of the victim, leaving only ash behind. The toxin is particularly terrible even among demon venoms, and there we are talking about a category that includes the poison of the Facemelter demon. (See “ Facemelter ,”.)
SHAX
These demons are known for their keen sense of smell and are sometimes summoned by warlocks to use in tracking a missing person. They must be carefully controlled, however; they are brood parasites and reproduce by wounding a victim and then laying their eggs in the still-living victim’s skin.

VERMITHRALL
Most Shadowhunters will incorrectly tell you that the Vermithrall is a monstrous lumbering mass made up of thousands of writhing worms. In fact the Vermithrall are the individual worms themselves. They do, however, collect into colonies in the shape of a humanoid and attack as a unified single entity. Worse, worms separated from the main body will endeavor to rejoin it, making it very hard to permanently kill a Vermithrall.
VETIS
They are not to be confused with Dragon demons, which they somewhat resemble but are unrelated to. They are gray and scaly, with overlong serpentine arms and an elongated but humanoid body. Like Dragons, they are known for hoarding valuables; unlike Dragons, they do not have any understanding of what is valuable and what is dross, and their lairs are more closely reminiscent of large rats’ nests than treasure chambers.
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MUNDANE DEMONIC CULTS

Through history there have been any number of pathetic, misguided groups of mundanes who have built small cults around the worship of a particular demon or group of demons. Most of these cults are of little interest to Nephilim and serve only to clutter and confuse demonic histories, since they are based around demons that are merely imagined or invented.
Nevertheless, a minority of these demon cults have successfully raised weak minor demons. These stories usually end with the cult improperly binding the demon and the demon immediately killing all of the cult’s members. In a small number of cases, a successful demon cult has endured for a short time, with the demon served by the cult members and asking little in return. These cults inevitably fade after a generation or two and are of little concern to us historically, but they may cause local trouble and require Shadowhunter intervention.
Mundane members of demon cults are often barely human by the time that intervention is needed. Their worshipped demon is likely to have consumed their humanity for fuel, to maintain and strengthen itself. This leaves behind mere shells of humans, their physical bodies in active decay and their souls worn down to a constant animalistic rage. This state is considered irreversible; killing these demon-degraded mundanes is considered an act of mercy and is thus within the bounds of the Law.
Cults have existed to serve Greater Demons, but there is little evidence that any of these have ever successfully summoned the subject of their worship. If they have, the likelihood is that they were immediately annihilated and no record exists of them to teach us of their folly.
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THE DEMON POX
Astriola, or demon pox, is a rare but debilitating illness that affects Shadowhunters and is caused by inappropriate contact with demons. The illness is not often seen, because this kind of inappropriate contact is, luckily, not common. Mundanes are immune to the disease; it is assumed to be caused by the interaction of demon poisons with the angelic nature of Shadowhunters.
The first signs of demon pox are a shield-shaped rash on the back of the sufferer, which then spreads over the body, creating fissures in the skin. From this point