Metroid Husk

Metroid Husks are the discarded membranes of Metroids. As a Larva Metroid evolves, it will ultimately shed its membrane and grow into an Alpha, Gamma, Zeta or Omega Metroid. They appear throughout the areas of SR388 in Metroid II: Return of Samus and Metroid: Samus Returns. In the latter, a yellow pus or amniotic fluid can be seen leaking out of the cracked shell, and steam is given off of some of them, indicating a recent evolution. The purpose of the Husks is to point out that a Metroid is nearby, accompanied by the beeping of the Metroid Radar and/or Metroid Marker triggering on the Map (both in Samus Returns). They are named in the Map key of Samus Returns.

Several large husks are found in Sector 1 near the end of Metroid Fusion. Reaching the Docking Bays, Samus finds an even larger one. She is then confronted by a massive Omega Metroid, which presumably shed this husk. The husk disappears as the battle against the Omega Metroid begins.