Dragonborn are large and well built humanoids who resemble dragons. Their entire body is scaled, and their heads are reminiscent of their larger cousins. Dragonborn lack wings but some are born with tails which run in certain families, they also have talon-like claws for hands and feet, with three fingers and a thumb on each hand.
The colouration of a dragonborn's scales indicates the element they can create with their breath. Scale colours are mostly hereditary, but there can still be a lot of variance within families, and mutations can lead to completely different colours amongst kin.
You can find information on how to create dragonborn characters on D&D Beyond.
Distribution
In The Known World, dragonborn originate from Vatan – The Great Rift separating them from most other continents. Because of this, dragonborn outside of Vatan are very rare.
Arauglbrok
Being the only other landmass on Vatan's side of The Great Rift, dragonborn are more common in Arauglbrok than most other continents.
It should be fine to play a dragonborn on this continent.
Haelspur
Dragonborn are very rare in Haelspur, with only a few outcast families living on the east coast. Most do not venture further inland.
Consult with your DM if you wish to play a dragonborn on this continent.
Korona Morska
Dragonborn are almost nonexistent in Korona Morska, the few that live here are travellers from Tide and are most likely solitary.
Consult with your DM if you wish to play a dragonborn on this continent.
Rhak
Dragonborn are almost nonexistent in Rhak, the few that live here are travellers from Tide and are most likely solitary.
Consult with your DM if you wish to play a dragonborn on this continent.
Tabasamu La Miungu
Dragonborn are very rare in Tabasamu La Miungu, those who live here are travellers from Tide.
Consult with your DM if you wish to play a dragonborn on this continent.
Tide
In 600OK (3357) ten Dragonborn families travelled to Tide from Vatan, across The Great Rift, making landfall at Rhunelin. At first the elves were resistant to their arrival but these dragonborn lent their strength to the armies of Pauviel and helped the country end the war with Konungdómr in exchange for being allowed to settle.
Over the centuries these families inter-married and spread across Pauviel, with some travelling south to seek the warmer climes of their homeland, while many remained to make a new home in the North. There are now many dragonborn who no longer identify with one of the original families.
Consult with your DM if you wish to play a dragonborn on this continent.
Vatan
Vatan is the homeland of dragonborn so they are commonplace on this continent.
It should be fine to play a dragonborn on this continent.