Alpha Metroid

The Alpha Metroid is the second stage (fourth if counting the egg and hatchling stages) of a typical Metroid's life cycle, appearing in two games, Metroid II: Return of Samus and Metroid Fusion. When an infant Metroid reaches the Alpha stage, the closed membrane once at the top becomes the belly and it remains so for the rest of its life cycle (the membrane only increases in size), and a plated exoskeleton grows where the mandibles once were. The Alpha Metroid has two compound eyes, a horn on its forehead, two small tusks, and incompletely developed limbs running along its sides. Instead of the three nuclei like normal metroids, the Alpha only has one, more like the Mochtroids, failed artificial replications of Metroids by Space Pirates.

Samus Aran encountered fifteen Alpha Metroids during her mission to SR388.

Behaviour
The Alpha Metroid has very basic and straightforward movements, so it doesn't pose any large threat. Five Missiles will take this creature down.

Manual
"This the [sic] shape of a Metroid after its first molting."