Metroids are predatory, floating organisms that possess the ability to siphon life energy from other living creatures. They were created by the ancient Chozo race to combat the dangerous X Parasites on the planet SR388. Throughout the series, they are sought after by Space Pirates who attempt to weaponize them.
The creature first appeared in the 1986 Nintendo Entertainment System release
Metroid, which saw various regional and physical iterations including the
Metroid [Disk System] version and the early
Metroid [5 Screw] cartridge variant. These early releases established the creature's distinct visual design, characterized by a translucent membrane exposing a red, multi-nucleated core.
As the franchise expanded, the creatures became central to various compilations and fan-made projects. They appeared in unique formats such as the
Super Metroid and Zelda: A Link to the Past Double Pack and inspired community-created modifications like
Super Metroid Darkholme Hospital and its homebrew counterpart
Super Metroid Darkholme Hospital [Homebrew].
Over decades of game design, these creatures evolved from simple 8-bit sprites into complex, multi-stage organisms. Their impact on the industry is profound, lending their name to the "Metroidvania" genre, which emphasizes exploration and backtracking. The creature's legacy persists as one of Nintendo's most recognizable and enduring sci-fi symbols.