Omega Metroid

The Omega Metroid is the seventh and final stage of a standard Metroid's life cycle.

An Omega is a fully grown adult and an extension of the Zeta Metroid stage. As a result, their body structures are very similar. Though they are sluggish compared to their prior form due to their greater size, Omega Metroids more than make up for it with their increase in raw strength, more powerful projectiles and enhanced body armor. Curiously, an Omega Metroid's body can have slight variations depending on unknown factors. One of these factors however may be based on the environment it grows in, similar to how a Larva Metroid adapts outside of SR388.

Samus Aran encountered four Omega Metroids during her mission to SR388. She would later fight another Omega Metroid created by Galactic Federation experiments on the Biologic Space Laboratories research station.

Metroids born with a specific gene can become a Queen, and while it is unknown if these gifted individuals follow the same life cycle as a standard Metroid, the resemblance between an Omega and a Queen suggests the former metamorphoses into the latter.

Metroid II: Return of Samus
The Omega Metroids fight identically to their Zeta counterparts: levitating around and periodically pausing to spit deadly acid. While slower than the previous form, the Omega can deal a very high amount of damage. Samus can Screw Attack into the creature, which causes no damage to her, but this will also not harm the Metroid. They keep the same weaknesses: Samus must shoot them either in the stomach or back, although a shot to the latter causes more damage, and shots fired straight up from underneath do no harm. Without utilizing their weakness, they require 40 missiles to bring down.

They maintain the basic structure of their last forms, though their posture are less hunched and their tail seems to abruptly end at a short length. Their artwork presents them with elongated jaws, contrary to their in-game, shorter leech-like mouth. They also feature what appears to be fur under their neck, and their eight compound eyes are colored blue. All Omega Metroids in the game are fought in Phase 8, an area that was split into and renamed Area 6 and Area 7 in the remake.

Metroid: Samus Returns
Owing to it being a remake of Metroid II, Omega Metroids make a return and were given a significant redesign. They are now massive in size and, like the previous Zeta Metroid stage, no longer levitate similar to Metroid Fusion 's Omega Metroid, therefore retconning their small and floaty appearances from the original game. Their arms are far longer in reach and their tail is fully complete as well. They also possess spine-like armor around their torso and five red eyes on each side of their head. Instead of spitting blob-like projectiles, they now fire a flame-based beam from their mouth. Finally, they are significantly more durable; their backside is no longer an exploitable weakpoint and their weak membrane is protected by a thick rib-cage coating that can regenerate over time. This protection can be destroyed with any of the Omega's standard weaknesses (Ice Beam,Missiles, Super Missiles, Beam Burst), but can otherwise be destroyed instantly with a Power Bomb. Its leech-like mouth is also a weak point, though significantly less so than the aforementioned membrane.

Like in Metroid Fusion, Omega Metroids defend their territory aggressively and are formidable foes capable of causing high amounts of damage to Samus despite her Gravity Suit's defenses. They can attack using their claws and tail swipes, sometimes in tandem. On occasion, Omegas might immediately smack Samus with the back of their hands if she positions herself too close behind them. The continuous red fire beam they unleash from their mouth leaves the surface it touches on fire. This beam is fired straight ahead, though they can also simply aim at Samus' position in the room, requiring Samus to Space Jump over it. Occasionally, the Omegas will sweep the beam upwards or downwards; when they do the latter, they inadvertently leave their membrane vulnerable but also force Samus to roll under them in Morph Ball form. The Metroids can also slam their tail against the ground, creating small earthquakes that cause debris to fall from the ceiling. Interestingly, the falling hazards can damage her through the Screw Attack, yet the former can be destroyed with her other weapons for health and ammo pickups. The earthquake attack can be used simultaneously with a variant of the red beam attack in which they fire straight down and spread fire across the entire floor. This forces Samus to continuously remain in the air by Space Jumping while also dodging the rocks falling from above. Despite being more sluggish than their prior form, Omega Metroids are surprisingly agile for their size, as they are capable of making large jumps. Finally, they can also perform a bite attack that can be parried with a Melee Counter. If parried successfully, Samus can followup with a special sequence of attacks consisting of Samus landing on top of the Metroid's chest and taking point-blank shots at the membrane.

Samus encounters her first Omega Metroid after activating the first Chozo Seal in Area 6 which incorrectly shifts the Purple liquid around and traps Samus in the same area. This Omega is implied to have recently matured from its Zeta Metroid stage, as the latter's husk can be seen lying in the background of the room before it is trampled as the creature charges in from that same background and engages Samus in combat after creating its rib-cage armor. After its defeat, Samus uses its DNA to activate a second Chozo Seal, correcting the previous' shifting of the hazardous liquid and granting her access to the Area 7 where the Metroid species were originally created by the Chozo.

Metroid Fusion
Samus encounters a single Omega Metroid on the BSL research station. It was originally an Infant Metroid from the Restricted Laboratory, developed from the cells of the Baby. It escaped during the laboratory's destruction, and went to feed on numerous X Parasites, rapidly molting through its life cycle until reaching the Omega stage as it made its way to the Docking Bays. Samus begins to find discarded membranes in Sector 1 and passes through several rooms, usually filled with X organisms, empty and in ruins.

Samus enters the Docking Bays, hoping to make a swift escape from the Station. Instead of her ship, however, she finds a giant shell larger than the Baby lying amidst the wreckage of the Docking Bays. As Samus begins to run back, the Omega Metroid bursts through the wall. This specimen is much more powerful than those encountered on SR388, as none of Samus' current weapons seem capable of damaging it, and it reduces her health to critical levels in one swipe. She is left with 1 point of Energy and is unable to move. As the Omega Metroid moves in for the kill, an SA-X, which had recently been defeated by Samus but was able to escape, joins the fight. The SA-X reacts adversely to the presence of its natural predator to the point of ignoring Samus completely. It moves right up to the Omega and shoots at the creature's membrane with the Ice Beam, revealing its weak point to her. The SA-X is then slashed by the Omega's claws, destroying its mimicry and releasing into the air the Core-X Samus had failed to absorb earlier. She leaps into the X, restoring all her health and returning the Ice Beam to her. This scene is likely an homage to the ending of Super Metroid, where Samus is saved from death by a former attacker and is given a powerful weapon to use against her enemy.

The Omega Metroid slowly creeps toward the left side of the docking bay throughout the duration of the battle in an attempt to swipe at Samus with its claws. To avoid this, Samus must use the Ice Beam to drive the creature backwards and move away before the Omega Metroid can counterattack. If the Metroid manages to connect with a claw swipe, Samus will take heavy damage (but not be reduced to 1 Energy, losing instead 100 Energy, ie. one bar) and be hurled backwards and knocked to her knees, exactly as she was at the beginning of the battle. Samus will stand back up after a few seconds, but since there is a countdown until the BSL collides with SR388 in effect, this is a battle not only against the Omega Metroid but against time as well.

Ultimately, Samus succeeds in driving the creature back to the wall through which it came, and is eventually destroyed. Samus's ship returns to the bay, allowing her to leave the station with moments to spare.

Inconsistencies
As previously mentioned, the Omega Metroids featured throughout the few titles in the series have several differences between them. In Metroid II and its remake Samus Returns, Omega Metroids are capable of firing energy-based projectiles from their mouths, however the single Omega present in Metroid Fusion does not demonstrate this and instead relies on physical attacks only. To add to its uniqueness, Fusion 's Omega Metroid has far more devastating power, as it is capable of depleting entire Energy Tanks in a single claw swipe. Furthermore, it is exclusively vulnerable to the Ice Beam, contrary to Metroid II which required Missiles. Samus Returns further defies these by making its Omega vulnerable to both missiles and the Ice Beam, as well as the Power Bomb.

In the official artwork of Metroid II, Omega Metroids possess blue compound eyes, a trait that began with the earlier Alpha Metroid stage. Later released titles have alternated this color between red and blue, as well as the number of eyes. The length of their tails varies as well, with Samus Returns having them at their longest. The most curious physical difference is the presence of four protuberances on the back of Fusion 's Omega. Other differences are subtle, such as larger claws along with fuchsia-colored membrane and nucleus. Similar to Metroid Larvae, these changes in strength, abilities, weaknesses and physiology may be the result of either the environments where the Omegas Metroids developed or the accelerated growth process used by the BSL Station's scientists. Another interesting difference involves the shed husk left behind by the Metroids when they reach the Omega form, as the one in the Docking Bay does not resemble the one seen in Metroid: Samus Returns. In fact, the husk seen in Metroid Fusion simply resembles the membrane of a Giant Metroid.

Metroid II: Return of Samus manual
"This mutation is absolutely huge; its power, incredible!"

Nintendo Power issue 31
"A fast and frenzied fight will ensue when you encounter this highly advanced creature. Be ready with Missiles."

Metroid: Samus Returns Official Guide

 * Omega Metroid (p. 22)
 * "The Omega Metroid represents the most advanced stage a Metroid can attain without being a Queen. These Metroids are massive, powerful, and can leap incredibly high and fast. Evolution has also done away with the Metroid’s trademark weak point: the core. While the core is still there, the Omega’s chiton armor plating hides it deep in its chest. The only way to reach it is to force your way in with explosive attacks, but even then, you have a short amount of time to strike before the chiton self-repairs and covers the core once more. Omegas are tough and shouldn’t be taken lightly. Expect to learn how to fight them in the school of hard knocks."

Trivia

 * The fact that the BSL Station's Omega Metroid left behind a husk resembling a Giant Metroid's membrane implies that its Larval form did not metamorphose into an Alpha, Gamma or Zeta Metroid and instead simply skipped to its adult stage when the larva reached a sufficient size. If it is the case, this is likely the result of the rapid growth process spoken of by the computerized Adam.
 * Danny Richardson made an artwork of an Omega Metroid during the early development of a sequel to Metroid Prime. It went unused when the game changed direction to become Metroid Prime 2: Echoes.
 * For unexplained reasons, the Omega Metroid from Metroid Fusion attacked Samus despite the latter having Metroid DNA, whereas the other Metroids in the Restricted Area ignored her. This may be because the Metroids in the Restricted Area were preoccupied with the SA-X who admittedly was attacking them at the time. Alternatively, the Omega Metroid may just be a generally violent creature and would have attacked any non-Metroid organism that entered the Docking Bay.
 * The battle against Metroid Fusion 's Omega Metroid is similar to the battles with Crocomire, the Kiru Giru and the Desbrachians, which all consist of a form of "tug-of-war".
 * The Omega Metroid is the only fully organic boss in Metroid Fusion not infected by the X-Parasites (the B.O.X. Security Robot is mostly composed of mechanical components), but this is only due to its natural immunity to the X that it shares with others of its kind.
 * The battle with the Omega Metroid is the second boss battle in Fusion to feature a time limit, after the scientist.
 * This particular Omega Metroid from Fusion is one of the few antagonists that succeeded in outmatching Samus. Mother Brain in Super Metroid, Ridley's battles in said game and and Metroid: Samus Returns, Dark Samus in Metroid Prime 3: Corruption and an SA-X were all similarly capable of bringing Samus to the brink of death.
 * The Omega Metroid in Fusion is only vulnerable to Samus' Ice Beam (stacked with the Power, Wave, Wide, and Plasma Beams). Therefore, it is the only Omega Metroid to date that Samus' Missiles (Super, Ice, and Diffusion) have no effect on it. This may be the result of the BSL's scientists tampering with its genes and/or using the aforementioned rapid growth process.
 * The Omega Metroid in Metroid Fusion drools some sort of substance after killing the SA-X. This may be the acid that others of its kind spat in Metroid II.
 * The Omega Metroid appears towards the end of the Metroid II commercial. It is the only enemy that is featured in stop-motion animation.
 * During the fight with the Omega Metroid in Fusion, Samus can be stunned by the Metroid's claws. The duration of this paralysis can be reduced by tapping up on the directional pad.
 * Oddly, the term "Omega" is usually used to describe the lowest-ranking member of a group, for example, in a pack of wolves.
 * The term omega is also the last letter of the Greek alphabet and is often used to describe the last of something, in this case most likely referring to this being the last stage of a typical Metroid's life.
 * The Omega Metroid in Fusion behaves similarly to the Arachnus-X in the same game. They both have a hunched posture, approach Samus slowly, and die while thrusting their heads repeatedly as they roar.
 * The Omega Metroids that Samus encounters in Metroid II are found in the same locations as their discarded shells. This implies they spent the majority of their life cycle in the same area.
 * In Fusion, even if Samus has one unit of energy left following her fight with the SA-X, the Omega Metroid's initial attack will not do additional damage; though she is still knocked down the event is scripted to leave her with one unit of energy no matter how much she had prior to the encounter.
 * The Omega Metroid in Fusion is currently the last encountered boss in the Metroid series (chronologically).

References and Footnotes
Metroid Omega Омега Метроид