Noxious gases are a toxic gas that has appeared in multiple Metroid games as a hazard.



As a defense mechanism, Blastcaps produce volatile chemicals in their fungal caps. A Blastcap will explode when it senses contact, releasing these chemicals in the form of a noxious gas.[1] This gas can cause damage to Samus Aran's Power Suit, but she can wait a few seconds for it to disperse harmlessly.


A Sky Puffer releasing noxious gasses.

Various noxious gases are present in the atmosphere of Elysia,[2] a gas giant planet in the Federation Solar System.

This gas may be one of the factors making the planet's atmosphere inhospitable for most life-forms. Very few native living creatures are encountered on SkyTown during Metroid Prime 3: Corruption; the city is inhabited almost entirely by mechanoids. The Galactic Federation once attempted to use the planet for research, but they eventually chose to leave only Aurora Unit 217 in SkyTown due to the atmospheric conditions; however, it is unclear if these "local conditions" refer specifically to the noxious gases or to the planet's notably harsh weather.

One native bioform that can survive Elysia's noxious gases is the Sky Puffer: a creature that feeds on the gas, particularly enjoying the Phazon gas present after the Elysia Seed impacted the planet. When killed, Sky Puffers will explode and release tan-colored gas from their bodies, which quickly dissipates. This makes it similar to the meta-viprium gas and Nohadin gas of other Puffers throughout the series.

Despite Elysia's atmosphere being inhospitable to humans, Samus Aran is able to survive in her Zero Suit as seen in the Special Ending of Corruption. Similar to Craterian Acid Rain, this may be due to the Chozo DNA she was infused with in order for her to be able to live on Zebes, since no mention is made of the the noxious gasses affecting the planet's former population of Chozo. However, gas emitted by Sky Puffers will cause damage to the shielding of her Power Suit.


A Groganch lobbing an orb containing noxious gas

The Groganch species is known to produce noxious gases contained in small globes.[3] This is the primary attack of the Groganch, which continuously lobs these orbs at Samus from the center of its body. Upon impact, they release their purple gases and deal damage to her Power Suit. However, Samus can shoot the globes before impact, dispersing the noxious gases from a safe distance.

Since the Groganch has only been observed as specimens aboard the BOTTLE SHIP, it is uncertain if the species naturally produces the noxious gases, or if this is a genetic alteration by the ringleaders to create a more efficient bioweapon.


  1. ^ Blastcap Logbook entry (Metroid Prime Hunters): "A large mushroom that explodes on contact, emitting noxious gas."
  2. ^ Sky Puffer Logbook entry (Metroid Prime 3: Corruption): "Sky Puffers are native to the planet Elysia. They feed on the various noxious gasses in the atmosphere. They are especially fond of Phazon gas."
  3. ^ Metroid: Other M Art Folio Samus in the Cryosphere Drifts: "One was new to me - a massive creature with a spiderlike body that lobbed globes containing noxious gas."