Dragonborn

"One of the more notable effects of the return of magic was the re-emergence of a humanoid race most commonly referred to as dragonborn. Contrary to popular belief, these Dragonborn are not related to Kobolds in any way and should not be met with the same wariness. Where Kobolds can be considered 'offspring' of dragons stunted by lack of access to magical energy, Dragonborn are the result of a humanoid race transforming into their draconic form by means of a magical ritual that binds the essence of dragons to their soul."
Reibac Hasirten, The Study of Dragons

Dragonborn are a powerful, draconic race born out of a binding between a humanoid's soul and that of a dragon. Unlike most races, Dragonborn do not reproduce nor are they born in a conventional way. Rather, they are the product of a ritual that binds them to the soul of a patron dragon through a magical ritual named 'reawakening'.
The reason for a humanoid creature to become a Dragonborn can differ from person to person, though oftentimes this reason is accompanied by what most would describe as a calling they feel from an early age. Because Dragonborn are reborn from many different humanoid creatures, their shapes and sizes can vary wildly in comparison to other races. This, however, is about the only physical characteristic that a Dragonborn will retain from their former selves. The reawakening is a complete transformation and will remove all characteristics such as tattoos, scars, burn marks and more. But even this has its limits. A person who starts their reawakening with a lost limb, for example, will not regain this upon their rebirth.
Because of their rarity and draconic appearance, Dragonborn are often met with wariness. Most townfolk with little knowledge of the arcane arts will mistake Dragonborn for kobolds and might even instinctively take up arms against a visiting Dragonborn adventurer should they feel threatened by their presence.