The Puromi is a living snake of fire. Due to its extremely volatile and destructive nature, Galactic Federation scientists have not been successful in capturing and researching this creature. During all attempts, the Puromi has melted and destroyed all scientific research equipment, even supplies that have been dubbed as "fireproof." It is unknown if the creature is able to survive outside of the acidic pool in which it resides.
It cannot be destroyed with any of Samus's arsenal and is mostly just an obstacle. You encounter two of these in a room where you must Screw Attack through pillars in order to get to the end of the room before it fills up with acid.
Its name is only found within the game's code.