Phazon Metroid

Phazon Metroids are only featured in Metroid Prime 3: Corruption. They are the result of Metroid Eggs being infused with Phazon.

Description
The mature version of a Miniroid, the Phazon Metroid is similar in appearance to Metroids, the differences being that a bony ridge splits their membrane down the middle, their larger talons are sharper and stick out more, and they have what appears to be a vestigial fifth claw on the back. In addition to this, Phazon mutation has also given them a tiny mouth located on their underside that has a small ring of smaller teeth surrounding it. If one latches onto Samus, she must go into Morph Ball form and lay a Bomb to get it off. She can also use the Hyper Ball to dispatch them while they are latched onto her. Unlike normal Metroids, Phazon Metroids have the strength to carry a Morph Ball into the air, limiting the effects of ill-timed Bombs and increasing their threat level. Despite these abilities, when a Phazon Metroid leeches energy, it does not increase in size like in the previous Prime games. In addition to their other abilities, they can temporarily warp out of local spacetime, making them intangible. They'll often do this to avoid being frozen by an Ice Missile, since they share the Metroids' weakness to cold; they cannot do so, however, when preparing to fly at a victim. They also cannot turn intangible if Samus shoots at them with her beams, as they travel much quicker than a Missile, and Hypermode can be used to destroy them quickly and effectively. A fully-charged Hyper Beam will destroy a Phazon Metroid instantly.

Their membranes have properties similar to Phazite, and cover a weak point that can be targeted with the X-Ray Visor and destroyed with the Nova Beam for a quick kill. Another unnatural trait the creatures possess is the capacity to fire a bolt of phazon energy that resembles an electric arc to engage foes at a distance, making them very dangerous opponents at long-range as well. These bolts can cause a hypermode failure.

The Phazon Metroids appear mostly in Space Pirate areas and on Phaaze. They can also be spawned by a Metroid Hatcher. The creatures known as Hopping Metroids are most likely a higher form of Phazon Metroids, as they are described as Metroids radically mutated by Phazon.

Phazon Metroids seem to have the capacity to make hives, as seen on Phaaze where they contantly respawn from structures in the walls positively identifed as Metroid hives in scans.

Trivia

 * When in the Xenoresearch Labs in SkyTown, and while the Phazon Metroids are still in their containers, one may notice that they have varying "personalities". While some will instantly go into attack position as Samus walks by their tanks, others merely chirp as they sway side to side or even simply ignore Samus.
 * The back claws of a Phazon Metroid resemble the tips of the second legs on Metroid Prime's first form, but their overall appearance (their shape and nuclei) shares more similarities with the same creature's core form, perhaps hinting at the possible connection between Phazon Metroids and Metroid Prime, though it could merely be a coincidence in design. However, the Hopping Metroid, presumed to be a later stage of Phazon Metroid, bears a greater deal of resemblance to Metroid Prime's exoskeletal form, and Prime-like husks can be found on Phaaze, a planet where large numbers of both Hopping and Phazon Metroids live.
 * Curiously, if one were to closely look at the Phazon Metroid's front above its fangs, facial traits can be seen: eyes, a nose and possibly a mouth are visible. The Metroid Prime's first and second forms had visible faces as well.
 * Another interesting trait that Phazon Metroids share with the Metroid Prime's second form is the ability to phase out of the local timespace, becoming invulnerable to all weapons except those of Phazon origin.
 * One other feature of the Phazon Metroid similar to Metroid Prime, is the mouth located on its underside. Metroid Prime's first form also has a mouth on its underside.
 * Oddly enough, they ignore Space Pirates and vice versa when they're in the same room and attack Samus Aran in tandem, unlike in Metroid Prime and Metroid Prime 2: Echoes. A logical explanation would be that both sides, being corrupted by Phazon, no longer see each other as adversaries (this has been noted in Pirate research experiment reports found in Prime) or the Phazon corruption had enslaved them to Dark Samus, forcing them to work together and defeat Samus, their master's primary nemesis. Another reason was that they were never scripted to encounter each other during programming.
 * The third reason seems most likely as Phazon Metroids can be seen feeding on Space Pirates in specific moments: dried bodies of Space Pirates can be found in the Xenoresearch Labs and the G.F.S Valhalla, and when shot at, they crumble to dust; undoubtedly the result of being drained by Phazon Metroids. Additionally, if the Metroids and Pirates truly worked together, the Pirates would have no need to imprison Metroids and render them docile in the Xenoresearch Labs and the Metroid Processing room.
 * Phazon Metroids can possibly survive in space as seen in the Valhalla, in which the predators can be witnessed floating through space; some enter the ship while phasing out of local timespace. The mentioned creatures seen outside out of the ship may, however, be dead Metroids (as they show no movements) and those that enter into the vessel could be from adjacent rooms. However, it does not seem possible that the Metroids could have died outside the ship, as the Valhalla battle was mostly inside the ship and Metroids do not seem to require oxygen to survive. Further proof of this is in Metroid Fusion, where an Omega Metroid was in the hanger bay of the Biologic Space Laboratories research station with a broken door showing the vacuum of space, possibly having the room decompressing.
 * Interesting to note is that while Phazon Metroids can be frozen by a simple Ice Missile, the cold vacuum of space has no affect on them, as seen on the G.F.S Valhalla.
 * Phazon Metroids on Phaaze are shown living within hives from which the creatures are constantly spawned. Also, an incredible amount of corrupted Metroid Eggs are present. The requirements necessary for a Phazon Metroid hive to be created were never revealed.