Infant Metroid

From Wikitroid, the Metroid wiki

The Infant Metroid is the first stage of a Metroid's life cycle. Upon hatching from its egg, the Metroid larva's body consists of a transparent, green membrane that surrounds four red nuclei. The larval Metroid also has large fangs. In this stage of life, the Metroid is impervious to nearly all forms of weaponry; it can only be killed by freezing the membrane and then shattering it with concussive weaponry.

On her first mission involving Metroids, Samus Aran was sent to destroy the Space Pirate base on Zebes and several stolen Metroid larvae. On a later mission to SR388, the Metroid's natural habitat, Samus destroyed all Metroids there, except for one newly hatched infant. This hatchling considered Samus its mother. It saved Samus's life in Super Metroid, by attacking Mother Brain and using the energy gained from it to give Samus the Hyper Beam, and shielding her with its body at the cost of its own life when Mother Brain revived itself. In Metroid Fusion, Samus was infected with the X-Parasite, nearly killing her. Metroids were discovered to be the X's natural predators and the Infant Metroid from SR388 had its DNA fused with Samus', saving her life again and making her invulnerable to future X-Parasite infection.

Issue 37 of Nintendo Power refers to this stage of the life cycle as a Bantee Metroid, in a walkthrough of Metroid II: Return of Samus.

Metroids
Natural Metroid Life Cycle	Infant Metroid • Metroid • Alpha Metroid • Gamma Metroid • Zeta Metroid • Omega Metroid • Metroid Queen
Tallon IV Metroids	Hunter Metroid • Fission Metroid • Metroid Prime
Aether Metroids	Infant Tallon Metroid • Tallon Metroid • Dark Tallon Metroid
Phazon-Infused Metroids	Phazon Metroid • Miniroid • Metroid Hatcher • Hopping Metroid