“Dragonborn” refers to an ancient race of half-dragons that had the bearing humans but possessed the power of Dragons. Their skin was scaly, they could breathe fire, and each had the strength of 10 men. Tales of the Dragonborn are just stories, however, relevant only in children’s tales and some of the more creative painters.
However, in recent years (though no one is quite sure when), a new race has been emerging from some of the mountains in the North. The S’engouer can’t patrol the entirety of the North, and there’s a large kobold population up in the mountains. A new strain of half-kobolds (no one is quite sure what the other half is) have been coming down from those mountains since the end of the Dark War. They are unsure of their own history, or for how long they have existed. They’ve lived in the mountains for as long as they and their ancestors can remember, but have only recently entered civilized lands. Some claim they are the descendents of the ancient Dragonborn, others lack such grandiose arrogance. Either way, the name has stuck, and that’s what these kobold breeds are now commonly referred to.