Dragon-worshipping cults are wide-spread and may vary from region to region, but they are all devoted to the worship of Tiamat and Bahamut through adoration of their avatars: Dragons!
Dragons are recognized as a power separate and beyond the control of the Creator Gods, an equal power that can be tapped by Dragonborn, Kobolds and even Humans who have rejected the Creator Gods.
Pyramids were the first structures built for the express purpose of worship, built by Dragon cults who leave sacrifices at the top for local Dragons to swoop in and pick up. A typical pyramid is square-based with a flat-topped, ziggurat-like shape and a broad flight of stairs leading from top to bottom. Most pyramids house the priesthood as well.
Collectively known as the Cult of the Dragon, they are the enemies of the Creator Gods and nearly every religious conflict in history has been between these two poles. However, there are also places where they co-exist peacefully, mostly in sophisticated cosmopolitan centers where church and state are clearly separated.
Alignment for any true believer should be in accord with their master Dragon. Chromatic or metallic, there are no Neutral Dragons, but cults may be Neutral for pragmatic reasons. However, Clerics and Paladins of the Dragon are almost always either Good or Evil.
Many Dragon Cults operate in conjunction with the local ruling body but sometimes (particularly in the case of Evil priesthoods) in direct control of a population. A single High Priest is presumed to have some sort of contact with the local Dragon and receive instruction from it, but this isn’t always true, in part because most Dragons couldn’t care less about anyone’s affairs but their own.