The nature of dragon kind and lizard kind has always been changing and blurred in Yurenth. While some Dragonborn are invaders from a foreign realm,
There has been a strange phenomenon where native species are laying a clutch of eggs will be unlike the other eggs. These eggs typically have chromatic and metallic looks. These eggs are Dragonspawn eggs, blessed by the gods of the dragon.
This phenomenon has been observed with lizardmen, dragons, kobalds, hydra’s and many other reptilian or dragon based creatures. When the egg hatches the offspring is almost always a dragonborn, but sometimes a dragon.
There is no known native Dragonborn in Yurenth, it seems strange because so many are actually born in the realm.