Seven Kingdoms: Seowyn's Crossing
Although they are warm-blooded, Dragonborn are hatched from clutches of eggs. A large chunk of eggshell is saved by one of the parents when a new dragonborn hatches. At the age of 15, a dragonborn undergoes his or her ceremony of Drathonas, signifying that they have come of age. This ceremony often involves a test, based around the declared future occupation of the one undergoing the ceremony.
These tests are rarely all pass or fail and are generally meant to teach the one taking the ceremony something about their own deeper nature.
During the ceremony, an adult relative presents the dragonborn with an amulet fashioned from their birthing shell. This amulet typically takes the form of a necklace, a belt piece, or a shield cap. It is considered terrible ill-fortune for a dragonborn to lose this amulet.