X Parasite

The X Parasite, also known as Unidentified Parasite Creature-X by the Federation^[1] and Erris (or perhaps Eddis) by the Chozo,^{[note 1]} is an extremely hostile, shape-shifting organism native to planet SR388. They appear in Metroid Fusion, Metroid: Samus Returns, Metroid Dread, and the prequel manga. They serve as the main antagonistic force of Fusion and the tertiary antagonists of Dread.

X Parasites are able to assimilate both the DNA and knowledge of other life forms, as well as to incorporate those features when they take new hosts, and their single-minded drive to consume and spread leaves them a threat to all other life in the cosmos, making it urgent to eradicate them.

The extreme danger of the X Parasites is what led the ancient Chozo to design the titular Metroid species, precipitating the events of the series. The galaxy at large learns of the Parasites in Metroid Fusion after Samus successfully eradicated the Metroids on their homeworld in Metroid: Samus Returns, and the detection of surviving X on ZDR in Metroid Dread forces Samus to once again confirm their extinction. Despite this risk, the extreme versatility of the X Parasite has led some among the Chozo and Galactic Federation to show interest in them as potential resources.

Biology and characteristics[]

An X Parasite's base form is a simplistic, airborne gelatinous organism approximately the size of a basketball with three particle-like structures that circulates within their mass like electrons. Their gelatinous bodies allow them to slip through the tiniest openings and, with few exceptions, harmlessly yield to projectiles. X Parasites reproduce rapidly and asexually, allowing them to quickly infest entire planets if not contained, and even in their base form they are able to quickly pursue and infect their prey. While X are incredibly mobile, base form X can still generally be contained, such as by using the vacuum of a Power Bomb to suck them in.

X Parasites are voracious, and once they locate prey, they infect the organism's nervous system and start reproducing at an exponential rate, consuming the host's soft tissue within seconds. It is during this process that the X absorb the DNA and memories of their victim, allowing them to replicate it and further their species' existence; this process is not prevented even if the host was already dead prior to infection. Depending on the situation, the Parasites may either begin mimicking the host's structure then and there, giving the appearance that the host has been possessed, or may simply consume it and create a facsimile at a more advantageous location. When Samus Aran was infected, the X did not appear to have an immediate effect, leaving her unaware of its deadly nature; when it later infested her central nervous system, she slipped into a coma and nearly died, and was only able to survive after being administered the Vaccine "Metroid". However, the X Parasite was still able to acquire her genetic and memetic information, producing the SA-X. The X Parasites are not limited to purely organic lifeforms—they are able to consume and replicate bio-mechanical technology, such as Samus' Power Suit or Security Robot B.O.X.'s neural network, and can even interface with technology to "download" similar data, as in the case of the Barrier Core-X. On a similar note, they can even copy DNA from fragments of an individual which is demonstrated with the creation of the SA-X from surgically-removed portions of Samus' Power Suit, with it also being implied in the case of Raven Beak X who's partially based on Kraid; in an earlier battle against the corpulent Pirate, the last belly spike he ejected into a wall prior to his defeat goes missing after the X have spread on ZDR. However, they are incapable of infecting inorganic beings, with E.M.M.I., Robot Chozo Soldiers, and other fully synthetic entities remaining untouched throughout Samus' journey on ZDR.

X Parasites are proficient at mimicking their prior hosts, allowing them to blend in and strike new unsuspecting prey, as was the case when an X had infiltrated Raven Beak's tribe on SR388 and kept them oblivious to its true nature until they arrived on ZDR. However, X Parasites mimicking Chozo have blank white eyes instead of their natural color; this trait is shared with SA-X, who would also have had Chozo DNA. X Parasites retain the information acquired from previous hosts and will often combine DNA from various sources to produce new forms more suited for combat; in a general sense, most X forms of wildlife possess more dangerous features than their source. Examples of this include Neo Ridley's oversized figure and Dessgeega's spike blasts. When X find themselves in danger or lose a fight, they will often incorporate features from a specific additional source. For instance, when Samus Aran was able to overwhelm an SA-X, it mutated into a more powerful, monstrous form that incorporated material from a previous Hornoad victim. On ZDR, the X went even further, fusing several sources with the form of Raven Beak into one behemoth hulk. Several of the Chozo soldiers of the Mawkin tribe also demonstrated the ability to mutate when on the losing end, such as having their eyes vanish and have their heads split into a gaping maw. However, it's unclear whether this was an extension of their ability to incorporate features from prior infected hosts or a wholly unique condition for ZDR X. When an X Parasite's host or imitation is destroyed and they are reduced to their base forms, the parasites will either try to immediately infect their attacker, withdraw in order to form a new manifestation for a renewed assault, or flee the vicinity entirely.

Despite normally being omnivorous, X may ignore potential prey. For example, the Dachoras and Etecoons found in the Habitation Deck, an X-infested area of the BSL station, were left uninfected and were allowed to escape to Samus' ship unhindered, which Adam speculated could be because the X believed them too weak or inferior for use. X may take their time hunting potential prey, as with the Hornoads in Sector 1 and Scisers in Sector 4.

The only threat to the X are the Metroids, specifically designed for that purpose. Metroids are anathema to the X even on a cellular level, and even the best efforts of the X do little to slow the Metroid's predation. Metroids drove the X population on SR388 to the brink of extinction. However, as soon as the X were accidentally freed from this threat by the actions of the Galactic Federation, they quickly rebounded and retook the planet. In addition, the X creating a form composed of various genetic sources could also in theory be capable of having them kill a Metroid.

With their great versatility, X are able to adapt and thrive in virtually any environment, even those alien to their homeworld. Most dangerously, the X appear to share either a hivemind or a devotion to the welfare of their species, making them willing to go to any lengths, even self-sacrifice, to triumph over their adversaries. In one event, one X attempted to overheat the Station, which not only would have killed Samus but also themselves. When speculating on the reason for this action, Adam states that the parasites must have felt Samus was a major threat to their entire species on SR388 and that the sacrifice of the X on board the BSL would have spared their brethren on the planet. Similarly, one SA-X destroys the Restricted Laboratory, which contained their Metroid predators, at the cost of its own life, sparing its brethren on the BSL from the Metroid threat, although this failed as one had escaped. The dire threat they would pose as a galactic plague if able to acquire spaceflight has made their eradication the highest priority any time they are detected.

History[]

Before Metroid[]

The X Parasites evolved beneath the surface of SR388 far in the past, and thankfully were trapped underground, until the Chozo discovered the X while mining for Aeion energy, naming it and learning of its abilities, which horrified them enough to consider it fundamentally "evil".

Recognizing the X's destructive potential, the Chozo created the Metroids in order to keep them at bay.^[2][3][4]

In the manga, the Chozo refrained from informing the Galactic Federation of the X Parasites because they accurately feared the Federation would seek to exploit them as a tool despite the risk in doing so.

Metroid prequel manga.

Metroid: Samus Returns[]

Per the orders of the Federation, Samus wipes out the Metroids on SR388, unknowingly allowing the X Parasites to recover their population, ultimately eradicating all natural life on the planet.^[5] They appear in the secret post-credits ending of Metroid: Samus Returns, infecting a Hornoad that was inspecting the Landing Site. They also appear in the game's Chozo Memories.

Metroid Fusion[]

The Federation first learned of the X on SR388 after Samus aided Biologic's research team in capturing native life forms; when Samus killed what was thought to be an ordinary Hornoad that attempted to attack the group, an X Parasite emerged from the carcass. The X promptly attached itself to Samus, but it caused no immediate issues and she shrugged it off. However, the X soon infested Samus' central nervous system and caused her to black out while piloting her Gunship, causing a crash that would have killed her if her emergency systems hadn't ejected her. The B.S.L. scientists recovered Samus' escape pod and brought her to Galactic Federation Headquarters for treatment.

They quickly found that Samus was infected by the X and had spread to her Power Suit, forcing them to surgically remove the infected portions. They sent these pieces to the B.S.L. research station for further study, inadvertently allowing them to mutate into the SA-X, but could not fully eliminate the parasites from her body without killing her. Fortunately, the Galactic Federation scientists were able to devise a vaccine using a cell culture from the last infant Metroid. As the Metroids had been designed to be the perfect natural predator of the X, the parasites in Samus' body were quickly and completely eradicated by the Metroid Vaccine. As a side effect of the vaccine, Samus' genetic makeup now included Metroid DNA, granting her the ability to safely absorb the X like the Metroids could, but also leaving her vulnerable to freezing temperatures (the primary weakness of the Metroids) and weakening her overall endurance. Shortly after Samus recovered from the infection, the Federation received a distress signal from the B.S.L. station. Samus was sent to investigate after the Federation provided her with a new suit, a new Starship, and a computerized CO to assist her in her investigations.

Once Samus arrives, she finds the station completely overrun by the X. At numerous points, the X attempt to stop Samus in her tracks by hunting her down, mutating into stronger forms, sealing off or destroying Data Rooms to obstruct her from her upgrades, and even destroying entire sectors of the station in an attempt to take her with them. However, Samus is ultimately able to commandeer the station, sending it on course to impact with SR388 in an immense explosion that destroys the laboratory and wipes out all life on the planet.

Metroid Dread flashback

Metroid Fusion Special Edition: Rebirth of Samus

Metroid Dread[]

Despite their apparent extinction, the Galactic Federation soon learned, via an anonymous video transmission, that some X had survived. The transmission is traced to planet ZDR and a team of E.M.M.I. robots is sent to investigate. When the E.M.M.I. go silent, they reluctantly call in Samus to investigate.^[6]

Although the hostile Raven Beak pretends, as part of his act as Adam, to suspect that the footage was staged, Samus eventually discovers that the X are indeed present on ZDR while investigating Raven Beak and the mystery of how the E.M.M.I. went AWOL. When Samus encounters Quiet Robe in Ferenia, the surviving Thoha informs her that one of Raven Beak's Mawkin soldiers was infected and copied during an expedition to SR388, bringing the parasite with it back to ZDR and spreading the disease to the rest of its fellows. Raven Beak contained the X Parasite within the Elun sector, but purposefully releases them after Samus examines the sector. The X quickly spread throughout ZDR and assimilate all of its organic life (including the deceased Quiet Robe), although they leave mechanical and non-hostile lifeforms unscathed. At one point, the X block thermal energy in Cataris from reaching the rest of ZDR, causing the global temperature to drop, until Samus kills Experiment No. Z-57 and removes the blockage.

Samus eventually defeats Raven Beak and crashes his ship, Itorash. Soon afterward, Raven Beak is infected by an X and mutated into Raven Beak X. Upon Raven Beak X's demise, ZDR suddenly begins to self-destruct, resulting in the annihilation of the surviving X species. Many X accost Samus as she runs back to her Gunship in an apparent last-ditch effort to kill her, although they are utterly destroyed by her Metroid Suit and Hyper Beam. Intriguingly, the X copy of Quiet Robe seemingly helps Samus control her Metroid transformation at the cost of its own life and for seemingly no benefit to the X species, allowing her to escape the disintegration of the planet.

Dread reveals that X-infected bioforms that were capable of speech before infection retain the ability to speak. This is demonstrated when Quiet Robe says "I am counting on you..." after being reanimated, and when Raven Beak X says "Samus... Hadar sen olmen"^{[note 2]} when crawling toward Samus. In both cases, the X repeated some of their host's final words prior to infection.

X Parasite hologram.

X Parasites escaping Elun.

Leaked footage uploaded to Nintendo's UK YouTube channel on September 16, 2021, showing a Red X Parasite in gameplay. The clip was later made private.

Development notes[]

The X resemble a species found on Zebes in Super Metroid called Boyon. In beta trailers for Fusion, the X originally reused Boyon sprites, albeit colored purple.^[7]

Base forms[]

Yellow X[]

Yellow X,^[8] or yellow parasites,^[9] are a basic type of X. When absorbed by Samus, they restore 10 units of Energy in Metroid Fusion and 40 energy in Metroid Dread. Yellow X come out of most normal enemies. A Yellow X was the X that infected Samus on SR388 after it flew out of a defeated Hornoad host.

Green X[]

Green X^[10][8] appear once Samus regains her Missile Launcher. Like Yellow X, Green X come out of most enemies. When Samus absorbs a Green X, two units of Missile Ammo are restored in Metroid Fusion and 5 Missiles in Metroid Dread.

Red X[]

Red X,^[11] also called red X parasites^[12] or red parasites,^[9] are usually only released from X-afflicted Gadora or stronger variations of normal enemies, such as the blue Zeros, although they can also rarely appear from normal enemies. When Samus absorbs them, they restore 500 units of energy, 50 units of Missile Ammo, and 10 units of Power Bomb Ammo (5 Power Bombs in Dread).

Notably, the X that absorbs Quiet Robe's body halfway through Metroid Dread is a Red X.

Blue X[]

Blue X (ブルーのX^?), also called Cold X (コールドX^?) in Nintendo Official Guide Book for Metroid Fusion, are blue-colored X Parasites that have been changed by the cold in Sector 5 (ARC) of the BSL station. Apparently, the X did this deliberately to both stop Samus from exploring the station and kill her.^[13] If Samus comes into contact with these X without the Varia Suit upgrade, she will unwillingly absorb them and be dealt a large amount of damage. This is due to the Metroid vaccine as Metroids are susceptible to ice, thus when she absorbs one of these X Parasite variants, she will be frozen from within.

When Samus first encounters them in Sector 6 (NOC), they are eager to be absorbed by Samus, and pursue her to achieve this goal. Samus must avoid them or else face death. She can fire her beam or Missile weapons to temporarily stun the parasites, allowing her to escape in the event that she is spotted by one. Once she reaches the Data Room in the sector and defeats the Barrier Core-X, she obtains the Varia Suit. When the Varia Suit is acquired, the Blue X can be safely absorbed, restoring 30 units of Energy. Immediately after obtaining the Varia Suit, several unsuspecting Blue X will fly towards Samus in the next room. After a few have been absorbed, the remaining ones will noticeably start to avoid her, and all existing Blue X within the two aforementioned sectors will now flee from Samus as soon as they detect her.

Interestingly enough, they are much larger in size as opposed to the yellow, green and red X, and are unaffected by the Power Bomb's vacuum ability. They are also the only type of X that are never seen taking the form of another creature. The Blue X's more solid nature might be directly caused by its cold characteristics, such as having a more solid/thicker form than other X (logically having its liquid structure being partially frozen) and an expanded body (similar to how water expands when frozen), both of which consequently make the organism more susceptible to being shot at.

The Blue X's newfound cold nature in Fusion could have given the X Parasites back on SR388 an advantage against the advanced Metroids initially inhabiting the planet, as the latter can be wounded directly with cold-based weapons (shown in both Metroid: Samus Returns and Metroid Fusion). Although the planet seemingly lacked a naturally occurring cold climate, the Chozo laboratory (initially blocked off by the purple liquid) had snow and ice present within a few rooms. It is unknown if the X Parasites ever reached the lab at some point, nor if the rooms would have been sufficiently cold enough to create Blue X. Dealing with the Metroid larvae would have required additional effort, as the Blue X would be unable to shatter them after encasing them in ice, as they lacked concussive weaponry. On the other hand, mimicking a large, powerful SR388 creature like Arachnus might have given them the firepower to shatter them.

No Blue X appear in Metroid Dread.

Adam informing Samus about Blue X.

A blue X chasing Samus.

Core-X[]

Core-X are X Parasites that either carry the DNA of a massive and powerful life form, or have absorbed advanced technological equipment. They protect themselves with a membrane casing that produces regular X Parasites when attacked. When Samus absorbs a Core-X, it restores 400 units of Energy, 50 units of Missile Ammo, and 10 units of Power Bomb Ammo in Fusion, but does not restore anything in Dread.

Orange X[]

"Orange X" are a new variant introduced in Metroid Dread. Multiple are seen in the cutscene where Samus leaves Elun for the first time, but they only appear in gameplay after Samus regains the Power Bomb. They restore 3 Power Bombs each.

Purple X[]

A single "Purple X" only appears once in Metroid Dread, at the very end. It infects Raven Beak shortly after his fight with Samus at Itorash, transforming the Mawkin Chozo leader into a monstrous creature. It also prominently displays features from Kraid, implying that this X had assimilated his DNA as well at some point.

Samus, thanks to her newfound Metroid Suit, manages to dispatch the monster with a well-placed Hyper Beam, doing the same to the Purple X after it reverts to its original parasitic form, obliterating it and leaving no trace of its existence.

Mini X[]

"Mini X" are smaller versions of X parasites that appear in Metroid Dread. They drop from small swarm enemies, such as Dizzeans. Unlike normal X Parasites, they stay where they were killed and cannot appear out of nowhere, change their shape, or fuse with other X. If left alone for long enough, they will simply despawn. They come in Green and Yellow, and appear to reuse the sprites of these colors from Fusion. Green Mini X restore 1 unit of Missile ammo, while yellow Mini X restore 5 units of energy.

Official data[]

[v] Metroid Dread Report 3 § 7
Profile Transmission The X parasite Profile This parasitic life form is one of the deadliest in the universe. It can inhabit living or dead organic creatures and use their host's genetic information to mimic them completely. The Metroid species was created by the Chozo to destroy the X. Thanks to Samus, the X have been reduced to cosmic dust along with their native planet, SR388. The X parasite ~Transmission from the Dev Team~ The story in this game starts with a mysterious transmission that implies the X—which Samus was gravely afflicted by and is thought to have destroyed in the Metroid Fusion game—may still exist. Are the X still out there, or is it something else? Please see for yourself.
Source

[v] Metroid Dread Report 5 § 5
Profile Transmission Immunity to the X Parasite Profile The Metroid were created to be the natural enemy of the X parasite. By receiving an emergency dose of the "Metroid vaccine"—created from a cell culture previously sourced from the Metroid hatchling—Samus became the only living creature who cannot be harmed by the X parasite. Because of her immunity, Samus alone is dispatched to planet ZDR to investigate the possible presence of the X parasite, a lifeform thought to have been eradicated. Immunity to the X Parasite ~Transmission from the Dev Team~ The X parasite is a terrifying creature capable of infesting any living thing, causing it to die, and then mimicking its host using the genetic information it copies. It's no exaggeration to say that the X is the strongest and most odious of lifeforms, as it instinctively prioritizes the preservation and expansion of its species, repeatedly dividing and merging to mimic stronger individuals. However, the only thing that can nullify its ability is the Metroid, which was created to be its natural enemy. Since the Metroid went extinct prior to the events of Metroid Dread, the only one who can rival the X is Samus, as she now has Metroid DNA in her.
Source

[v] Metroid.nintendo.com
X PARASITE Profile A terrifyingly lethal parasite that could take over organic creatures, mimicking them afterward based on their genetic information.
Source[14]

[v] Nintendo of America (@NintendoAmerica). 16 June 2021 11:05 a.m.
Profile The X is a lethal parasite that takes over organic creatures, mimicking their genetic makeup and threatening the galaxy. Samus once fought and wiped out the X along with planet SR388, but a mysterious transmission has indicated an X still possibly lives… #MetroidDread
Source

[v] Nintendo of America (@NintendoAmerica). 30 July 2021 3:30 p.m.
Profile The parasitic lifeform known as the X is one of the deadliest known. It can inhabit any organic creature and mimic them completely. Samus is believed to have destroyed them all, but a mysterious transmission in #MetroidDread implies some may have survived... or have they?
Source

Metroid Fusion manual[]

X - PARASITIC ORGANISMS
X (Unidentified Parasite Creature-X)

"X seem to have originated on SR388, which is also home to their sole predator, the Metroids. Since Samus Aran exterminated the Metroids on SR388, the X have overrun and infected most of the life-forms on the planet."

PROPERTIES OF X PARASITES

"X infected other creatures and grow in the nervous systems of these host organisms. Even more worrisome is their ability to control and assume the appearance and behavior of other life-forms through mimesis, a process of infection and replication. The X must somehow be capable of assuming the memories and genetic information of their hosts."

X PARASITES VS. SAMUS

"The X parasites react adversely to the presence of Metroid tissue and even associate the Metroid cells in Samus' body with their natural enemies. X parasites within reach of Samus will attack viciously and relentlessly."

ABSORBING X PARASITES

"Since receiving the Metroid vaccine, Samus has begun to incorporate some properties of Metroids into her own genetic makeup. This allows her to absorb X parasites in their gelatinous form to replenish her supply of energy and missiles. After defeating organisms infected by the X parasites, Samus must capture the X in its true form as it escapes from the dead host."

ENEMIES IMITATED BY X PARASITES

"All of the enemies Samus encounters are imitations of or infested versions of the creatures that were research subjects on the space station. Attack them to reveal the X parasites hidden within.
The X parasites take on many forms and attack from every vantage point possible. Use caution when moving through the space station."

Metroid Fusion: The Official Nintendo Player's Guide[]

X COLLECTION

"Once you've exposed the X parasites, you can grab them to recover energy, weapons or abilities. Yellow parasites refill 10 energy units. Green ones give you two Missiles. By collecting red parasites--the kind that you find after you destroy a hatch guardian--you can replenish energy, Missiles and Power Bombs. When you defeat and collect Core-X parasites, you will recover one of Samus Aran's lost abilities.
A special Metroid vaccine in Samus' body allows her to replenish energy and weapons by collecting parasites.
When you're fighting a Core-X creature, it will shed X parasites. Collect them to refill your energy mid-battle."

Metroid Dread loading screen tips[]

X PARASITES

Only Samus can counter the X parasite threat now that their sole predator, the Metroids, have been eliminated. She received this power from the infant Metroid DNA with which she was injected.

The X are parasitic organisms discovered on SR388 that can infect any living creature. They kill their hosts and absorb their DNA to assume the host's form.

An X that has possessed multiple hosts can combine their appearances and traits during the process of replication and morph into a new entity.

The X can even infect dead creatures and assume their forms using DNA absorbed from the corpses.

Other appearances[]

"What's the matter? All I said was that Komaytos look like little Metr-"

---

Non-canon warning: This article or section contains information that may not be considered an official part of the Metroid series in the overall storyline by Nintendo.

Super Smash Bros. Ultimate[]

In Super Smash Bros. Ultimate, the X Parasite appears as Primary Spirit, which boosts fighters' stats in game modes such as World of Light. It is represented with artwork of three Yellow X clustered together. The X Parasite's type is Attack, which gives it advantage over Grab Spirits but is weak to Shield Spirits, and its class is Advanced. Additionally, upon leveling up the X spirit to Level 99, it can be enhanced into the Nightmare Primary Spirit, which grants the wielder life steal in combat.

The X Parasite can be obtained through the Spirit Board or purchased from Beedle's Tent. In its Spirit Battle, the X Parasite uses Kirby as a Puppet Fighter, most likely since they are both blob-like beings that consume other creatures and copy their abilities. The player must defeat a team of ten Kirby Puppet Fighters appearing in their yellow "Keeby" alternate costume. Each Kirby is more likely to use their Inhale move to copy the player's character. The Spirit Battle takes place on Lylat Cruise, with Sector 1 as the background music.

Trivia[]

• Although Adam speculates that the X view the Etecoons and Dachoras as not being sufficiently useful to assimilate, the X have nonetheless infected other lifeforms that arguably have less potential when considering their respective abilities. An example being the durable yet extremely sluggish Ripper being chosen over the Dachora and its natural ability to Speed Boost. Additionally, the X's capacity to modify their victims by combining traits from other animals could have, theoretically, allowed them to make the Etecoons and Dachoras useful to them.
• Despite the X having gained hacking capabilities from their human hosts, they never attempted to open all the security hatches and invade all the sectors on the BSL, nor to re-lock the security hatches that Samus was using. It is also unknown why they disabled the station via Nettori.
• Strangely, it seems the X cannot directly assimilate or mimic plant life. In Metroid Fusion, the boss Nettori is revealed to be a Torizo controlling vines that are merged with it. When the smaller of these vines are destroyed by Samus' weapons, or when the larger ones wilt as a result of the boss' destruction, they do not revert to X parasites. Similarly, the Enky in Metroid Dread, which appear to be a plant or fungus, do not turn into X when destroyed.
• The fact that the X can infect and imitate their hosts appears to make them similar to the creatures from the science fiction horror film The Thing.
• The Chozo word for X uttered in Metroid Dread resembles the Spanish pronunciation of the letter "x", Equis, as well as the Greek God of Strife, Eris. However, exact transcribing is unknown until further official developer verification. While the exact creator of the Chozo language is unknown, this could have been influenced by the developers of Metroid Dread, MercurySteam, who are based in Spain.

Gallery[]

X Parasites in the Parasite commercial.

The red X that mimics Quiet Robe.

Notes[]

References[]