Dragon Egg

"All the jewels, all the treasures, Gaius, they don’t compare."

- Merlin about the Dragon Egg

Dragon Eggs are eggs from which dragons hatch. They are incapable of hatching on their own and remain dormant until the dragon is called into the world by a Dragonlord.

History
To ensure its safety, Ashkanar hid the last remaining dragon egg in a tomb meant for himself. He designed the tomb with numerous traps and divided the Triskelion that opened it into pieces that he hid throughout Albion.

Four hundred years later, Julius Borden stole part of the Triskelion from Camelot's vault. Merlin, Arthur, and the Knights of the Round Table followed Borden to the Tomb of Ashkanar, where Arthur meant to destroy the egg before Borden could steal it and use it for his own ends.

Merlin, however, wanted to retrieve the egg and return it to Kilgharrah, the last surviving dragon. He succeeded in his mission by defeating Borden with his magic and leading Arthur and the others to believe that the egg had been crushed when the tomb collapsed.

Merlin later used his Dragonlord powers to hatch the egg by naming the dragon inside Aithusa (Aithusa).

Trivia

 * Aithusa's egg is the first and only dragon egg to appear in the series (Aithusa).
 * Dragon eggs can live for over a thousand years waiting for a Dragonlord to call them forth (Aithusa).