Toxic Gas

"Toxic Gas" is the only name for a green, gaseous entity that is an unused enemy in Metroid Fusion. Whether it is a creature or not is unknown, and it has not been programmed with any vulnerabilities. Samus is not able to harm it with any of her attacks. It appears and disappears at regular intervals, but stays in one spot. If attacked, it will retaliate by creating a group of small explosions around it that do minor damage to Samus. Contact with this possible life form causes no damage to Samus.