The Zeta Metroid is the sixth natural stage of a Metroid's life cycle. They appear as enemies in Metroid II: Return of Samus and its remake Metroid: Samus Returns. They also have a minor appearance in the Restricted Lab of Metroid Fusion.
The Zeta Metroid possesses a very different structure from all prior forms, as it now resembles a theropod dinosaur. This stage is the beginning of the species' adult phase, and thus requires a lot of firepower to kill. Although the Zeta Metroid no longer flies in Metroid: Samus Returns, it has high agility and is capable of climbing any surface. The Omega Metroid is the next and final stage for all standard Metroids.
In Metroid II: Return of Samus, Samus Aran encounters three Zeta Metroids during her mission to SR388, while in Samus Returns there are four Zetas.
