The Dragon Egg is the first stage of the Dragon, the super unit of the ∑∫ỹriȱŋ tribe. The Dragon Egg grows into the Baby Dragon at the end of the third turn after the Egg is spawned; the Baby Dragon grows into the Fire Dragon after three more turns.
The Dragon Egg itself is weak, with only 10 health, but it is a valuable target because it can grow into the powerful Fire Dragon. Therefore, the Egg needs to be protected from enemy attack. One way to do this is by moving the Dragon Egg away from the front lines.
Because the Dragon Egg has so little health, it cannot effectively stop a city siege. However, upgrading a city before it is captured may prevent the enemy from producing a super unit there.