Kobolds

The first kobolds appeared on Emeriss shortly after the shard of Orcus crashed into the Caraecol Mountains and goblins began plundering the lairs of the world's dragons. While almost no number of goblins could slay a dragon, the presence of a great wyrm did little to dissuade the most careful, cunning, and courageous of these green-skinned newcomers from stealing treasures and even eggs from beneath a dragon's very nose.
No one can say for certain which dragon was responsible, but by pulling a scale from its own body, patiently molding the scale into an egg shape, and incubating it in their own breath, they hatched the first kobold. Utterly devoted to the will and well being of the dragon who created them, these tiny creatures made not only ideal guards against goblin burglary but also excellent errand runners, companions, and for some more arrogant dragons, even worshipers.
Within a thousand years, virtually every dragon on Emeriss had a tribe of these clever creatures protecting, living in, and expanding their lairs.
Then came the ancient Durasian Empire and their Great Gate. Heroes backed by entire armies flooded the lairs of dragons across the realm, hunting the great wyrms for their bones, their breath, and their treasure, and scattering their kobold survivors to the wind.
In the absence of a dragon around which to orient their lives, many kobold tribes - chromatic and metallic, both - fell to raiding farms and simple thievery in order to survive. Where once they were the favored children of some of the most powerful creatures in all the world, they now found themselves reduced to little better than the goblins they had been created to oppose.
Out of sheer desperation, some tribes have been known to pledge themselves to dragons of another color (though they rarely cross the boundary between chromatic and metallic) or even to swear fealty to a particularly impressive dragonborn.
Even so, many tribes have not forgotten their original purpose. Passed down from one generation to the next, they remember the hoards of their masters, the locations and scope of their lairs. It is not at all uncommon to find a pack of silver kobolds pillaging ancient ruins, white kobolds burgling a glassworks, and red kobolds raiding the homes of both while they are away - all in the hopes that if they collect enough treasure, if they can build a resplendent enough lair, then a new dragon will come and give the tribe some purpose beyond basic survival.