Glow Flies are insect-like creatures that appear in Metroid II: Return of Samus and its remake Metroid: Samus Returns. In Metroid II, when dormant, they stick upon the wall with their abdomen flashing. When Samus comes close, they will curl and launch themselves at her. If they miss, they will re-attach to the opposite wall.

In Metroid: Samus Returns, Glow Flies attach to the ceilings and walls and go in a small path between two tunnels. If Samus stands in one's way, it will unleash a small explosion, damaging her but also killing itself.

Official Media Edit

Metroid II manual
"When dormant, they stick upon the wall with their abdomen flashing. When Samus comes close, they will roll up and crash into her."

Metroid: Samus Returns Official Guide

Inhabitants & Eco System of SR388 (p. 19)
"These volatile insects are all too willing to self-destruct in the service of what we assume must be their queen. They make their way from one hole to another with unbreakable focus and singular purpose. Should anything get in their path, their defense mechanism is to explode, dealing heavy damage in the process. Give these creatures a wide berth. If you end up on a collision course with one, shoot them well before they get to you, or suffer the consequences."
Walkthrough (p. 79)
"If you go after [the Missile Tank], you run into this volatile ant-like insect. Entering this creature’s line of sight causes it to pop, which creates a sizable explosion from its bulbous hindquarters. As if that weren’t troublesome enough, these exploding nuisances continuously crawl out of their hole, even after detonating. The good news is they’re single-minded; they always walk from their own anthill to the next-closest one. Exploit this trait to manipulate their movements—open a path to another anthill and watch them run directly to it.

Note: Although our zone maps mark Glowfly locations with the red enemy variant, expect to encounter the common green Glowfly far more frequently."


  • It is unknown if the Glow Fly species was infected by the X Parasites, as Samus never encountered any Glow Fly-X in Fusion.
  • These insects appear to resemble the Plazmite of Tallon IV and the Fire Flea of Zebes. Whether or not there is a connection between them or this is simply a case of three separate species convergently evolving is unknown.

Gallery Edit