Maw

A "Maw" is a large life form native to the planet Phaaze. One of these life forms is seen living at the bottom of the Drop Shaft, underground. When it senses prey, it opens up, revealing a massive jaw, ringed with large fang-like teeth, that opens up itself, revealing a smaller jaw with a ring of tentacles that appears to be made up of Phazon or a substance similar to it. It should be noticed that it appears to expel clouds of Phazon-like gas from holes around its mouth. When it captures "prey", the inner mouth engulfs it and is then pulled into the larger one, which closes shut yet remains above the ground. It is most likely a species of passive predators, waiting for potential prey to fall onto it, based upon its apparent sedentary lifestyle. Scans indicate that this Maw is part of a much larger organism.

This life form is slightly similar to a hydra or sea anemone in appearance. It is also slightly similar to an enemy in the Half-Life series, the Barnacle, save for being upside-down.

While the most common tactic to kill the creature is to get caught by it and use the Hyper Ball, there is another way to avoid it. When Samus begins falling down the tunnel that leads to it, she must hug the wall in Morph Ball, then begin charging her boost. Once she hits the creature, she must activate her boost, so that she will shoot past it. There appears to be no other way to kill it, aside from Hyper Ball.

Metroid Prime 3: Corruption Premiere Edition refers to this as an "alien creature".

Scans

"Maw appears to be a small portion of a much larger organism. Will attack if within striking distance."

"Maw has been destroyed. Fleshy mass appears to be part of a much larger organism."