The Cult of the Wyrm
The Cult of the Wyrm is the name given to the various small (10 - 50 members, max) militant, religious, and political cults that build up around the worship and veneration of a single or mated pair of chromatic dragons. The aims and goals of these cults are varied, but in general they center around the elevation of chromatic dragons' control of the world--either the explicit overthrow of governments, or the subversion of those governing bodies, or the elevation of Wyrmcultists into positions of power within a religious body, and so on.
While Wyrm Cults often are aware of other cultists' activities, in general the Wyrm Cults each act alone, and on the direct orders of their draconic leader, which means that while two or more chromatic dragons might work together to accomplish some specific aim or goal, long-term partnership is never a realistic option and eventually the Cults will work to betray and/or backstab the other, sometimes with draconic approval or even participation.
Cult cells have been found in all corners of Azgaarnoth, particularly anywhere remote where a young chromatic dragon might be able to grow without attracting notice. They tend to lie low, particularly in more population-dense areas, since rumors of a Cult cell has been known to draw unwanted attention.
Relationships
The cult has a long-standing open war against the Draconic Order, and cultists will never miss an opportunity to cause any sort of damage (political, economic, or otherwise) to a chapter, particularly if they can embarrass them or outright destroy a chapterhouse or cell. Doing so will often raise the cultist's standing in the dragon's eyes; some cultists see doing so as the principal means of advancement in the cult. In return, Draconic Order expeditions have been known to cross the entire length of the continent to stamp out a Wyrmcult cell, slaying the chromatic dragon if possible.
It is rumored that the Dread Emperor has made contact with several cells of the Cult, and offers them sanctuary in return for favors; if this is true, it means the Emperor has taken a dangerous step, for allies of chromatic dragons are generally not long for this life... but the same can be said of the allies the Emperor if they distract him from his goals.
Thanks to their clandestine nature, Wyrmcults are natural partners with many Rogues' Guilds, though such partnerships are often out of mutual benefit and not any particular loyalty; a cult will give up a guild without a moment's hesitation if doing so would aid the cult or distance it from guild-inspired trouble, and vice versa.
Periodically, a Wyrmcult will infiltrate or partner with a Mage School, usually at the bequest of the dragon, who seeks either arcane knowledge or opportunities for arcane experimentation. Some dragons have even been known to seek to found a school as a cover for other operations.
The chaotic nature of the dragons (and thus their cults) usually keeps them from close association with Monastic Orders, though in times past some orders have found interesting advantage in such partnership (and vice versa). It is rumored that there is even a secret "Order of the Wyrm", a monastic order dedicated to the same goals as the Wyrmcult, but no (credible) evidence of such has ever been presented.
Structure
A Wyrmcult is usually made up of a single leader, often a powerful martial (Fighter, Ranger, Barbarian) or arcane (Bard, Sorcerer, Wizard) figure. That leader usually has direct contact with a chromatic dragon of Young to Adult age. (Younger dragons are often still too young to do more than just survive, and older dragons often operate on a larger scale than a single Wyrmcult.)
That leader will in turn have several lieutenants and trusted assistants to execute many of the day-to-day operations, most often from the arcane, martial, or roguish classes. (Divine members are less common unless they are devoted to Tiamat or one of her celestial allies.) These will often be split between schemers (that seek to improve their own standing or reduce their peers' efforts) and "true believers" (whose devotion to the cult's larger goals is unshakable). Some may even be thralls of the dragon, sent to keep an eye on the cult leaders, to ensure they remain aligned with the dragon's own goals.
The bulk of the cult's membership will be 20-40 minions/cultists that do the bulk of the "dirty work". These will often know each other directly, and members will often discuss potential future recruits before any are actually approached. Most cultists will hold some position within their surrounding environment (farmer, artisan, merchant, etc) and often are able (and asked) to make use of that position to aid the cult in some capacity.
Most cultists join in hopes of gaining power, either political or arcane, but some few join out of desperate desire; it is not uncommon for a cultist to join in hopes the cult will be able to help save the family farm, for example, or to help offset threats from a rogues guild or merchant guilt. These cultists will often be reluctant to engage in some of the more profane rituals, and almost all don't last within the cult for long.
The Cult of the Nightwyrm
A rumored sub-segment of the Wyrmcult is those that are dedicated to the raising or creation of dracoliches (draconic liches) and others like them. These groups operate very secretively, as both the Draconic Orders and the Wyrmcultists are threatened by such creatures, and will immediately move to destroy any such creature or cult cell they find.