- Queen Hive
Metroid Eggs are laid by the Queen Metroid in large numbers. Each egg is approximately one meter in height and contains an embryonic Metroid that rapidly matures to its Hatchling state. Inside the egg, the Metroid is kept in a state of suspended animation, feeding on the nutrient-rich fluid inside. The transparent shell itself is tough and rigid, and can only be damaged from outside by explosives. However, the interior structure is weak enough for a Hatchling to crack it from the inside. Eggs can either be triggered to hatch or will hatch on their own if signaled by the Queen Metroid.
Metroid Eggs are anchored to the floor at the base by a thick web of sticky root-like structures. This webbing keeps the Egg upright. In addition, this webbing appears to serve as a trigger system, detecting subtle vibrations in the ground from creatures or machines moving nearby, and causing the Metroid Hatchling to awaken. In this fashion, the egg will hatch explosively, releasing the Hatchling.
Although several Metroids are encountered before the Queen Metroid’s chamber, there is only one egg, containing the Baby Metroid, and Samus cannot destroy it. Samus initially sees the egg by rolling through a passage beneath it. This triggers the final brood of Metroid Larvae to appear, suggesting they, too, have hatched from Eggs. Samus can only reach the Egg after defeating the Queen Metroid. It contains the last Metroid in the Galaxy.
Metroid Eggs were described in detail in the Metroid: Other M art gallery.
According to the Metroid instruction manual, the Galactic Federation research team that first charted SR388 discovered the first Metroids in a state of suspended animation. Although they were contained in what was said to be a "capsule", it is possible this was in fact an egg.
Metroid Eggs superficially appear similar to Xenomorph eggs from the Alien series, although they crack open rather than peel outward like a flower.
Using Secret Worlds, Samus can come upon the egg from behind. It is programmed to hatch when Samus is several pixels away, meaning it can hatch from either side.