- This article is for the music in Metroid II: Return of Samus and Metroid: Samus Returns. For other uses, see Baby Metroid (Disambiguation).
Met2 Metroid Hatching is a theme in Metroid II: Return of Samus and Metroid: Samus Returns. It is associated with the baby, an Infant Metroid that imprints onto Samus Aran near the end of both games. In contrast to most of the music in both games, this theme is uplifting and almost cathartic. In Return of Samus, the theme begins after the defeated Queen Metroid finishes disintegrating, and continues as Samus reaches her Gunship with the baby. It was composed by Ryoji Yoshitomi.
In Samus Returns, the theme is remixed with Metroid Prime series-style instruments. Whereas it was repetitive in the original, this new version adds piano segments and different bars to make it less so. The mood of the song altered to sound more triumphant and energetic, but also with an underlying somber tone. This time, it does not play while the baby hatches; instead, Boss Go plays throughout the Queen's nest. Met2 Metroid Hatching begins to play as Samus and the baby enter the next room, and only plays in this room; as soon as they reach the Surface via an Elevator, a remix of Planet Zebes - Arrival on Crateria from Super Metroid begins to play.