{{short description|none}} {{Multiple issues| {{more citations needed|date=December 2018}} {{In-universe|date=May 2011}} {{Update|''Metroid Prime 4: Beyond''|date=December 2025}} }} {{Use mdy dates|date=November 2025}} {{ititle|Metroid}} {{nihongo foot|''Metroid''|メトロイド|Metoroido|lead=yes|group=lower-alpha}} is a series of nonlinear science fiction action games published by Nintendo, featuring side-scrolling, metroidvania, and first-person shooter elements. The player character and protagonist of the series is Samus Aran, a space-faring bounty hunter who battles Space Pirates and a species called the Metroid.
==Major characters== ===Samus Aran=== {{main|Samus Aran}} {{nihongo|'''Samus Aran'''|サムス・アラン|Samusu Aran}} is a bounty hunter and the protagonist of the series. Prior to the events of the series, her homeworld was attacked by the Space Pirates, and her parents were murdered by their leader Ridley. This led to her being taken in by the Chozo aliens, who saved her life and raised her to become a warrior. She wears a futuristic suit equipped with armor, blaster cannons and other weapons such as missiles. The additional protection provided by the suit allows Samus to survive on other planets. Samus also appears in the ''Super Smash Bros.'' series as a playable character.
=== Ridley === {{main|Ridley (Metroid)}} {{nihongo|'''Ridley'''|リドリー}} is a high-ranking Space Pirate and major recurring antagonist who serves as Samus's archenemy. A draconic entity, he is defeated by Samus multiple times, but is always revived by the Space Pirates (or accidentally by the Galactic Federation in ''Metroid: Other M)'' using cloning or robotics. Other than Samus and the titular Metroids, Ridley is the only character to appear somewhat consistently throughout the main series, though only in first entry of the ''Prime'' sub-series. He is directly responsible for the invasion of Samus' home planet and the death of her parents and is the franchise's most frequently recurring villain, though he doesn't typically act as the primary antagonist in individual games. Outside of the Metroid series, Ridley (in cyborg form) is a boss in the campaign of ''Super Smash Bros. Brawl'' and a playable character in ''Super Smash Bros. Ultimate''.
=== Mother Brain === {{main|Mother Brain}} {{nihongo|'''Mother Brain'''|マザーブレイン}} is a brain-like supercomputer and the main antagonist of ''Metroid'', its remake ''Metroid: Zero Mission'', and ''Super Metroid''. The Chozo created it as a councilor, and as a means to "accelerate their plan to link the galaxy into one unified society".<ref name="Archived copy">{{Cite web |title=Metroid Database :: Metroid, Volume 1 (English) Chapter 7 |url=http://www.metroid-database.com/manga/?vid=19&cid=61#manga_top |url-status=usurped |archive-url=https://web.archive.org/web/20161231171105/http://www.metroid-database.com/manga/?vid=19&cid=61#manga_top |archive-date=2016-12-31 |access-date=2016-12-31}}</ref> Mother Brain is depicted as a large brain with cybernetic spikes and a single eye, usually contained in a glass tube which Samus must break in order to injure it. In ''Super Metroid'', Mother Brain also rises from the floor and reveals a grotesque body after her tank is destroyed. In the ''Metroid'' manga, during the Space Pirate invasion of Zebes, it sees the Space Pirates as a "perfect force capable of restoring true order to the universe", and successfully established itself as one of their leaders.<ref name="Archived copy" group="‡">{{Cite web |url=http://www.metroid-database.com/manga/?vid=19&cid=61#manga_top |title=Metroid Database :: Metroid, Volume 1 (English) Chapter 7 |access-date=2016-12-31 |archive-url=https://web.archive.org/web/20161231171105/http://www.metroid-database.com/manga/?vid=19&cid=61#manga_top |archive-date=2016-12-31 |url-status=usurped}}</ref> At the same time, Mother Brain attempts to persuade Samus to be an ally in order to "build a new age for the universe" by claiming that because it built the power suit that Samus wears, she is indebted to Mother Brain.<ref name="Archived copy" group="‡" /> Samus seemingly destroys Mother Brain in the original ''Metroid'', but again confronts it in ''Super Metroid''. It was revealed in ''Metroid Prime 3'' that the Galactic Federation had constructed biomechanical supercomputers called Auroras, and that there were plans for a "Future Aurora Complex", which appears to be the Mother Brain depicted in ''Super Metroid''.<ref name="brain">{{cite web |author=Matt Casamassina |date=August 14, 2007 |title=The Return of Aran's Fiercest Enemy |url=http://wii.ign.com/articles/812/812862p1.html |url-status=dead |archive-url=https://web.archive.org/web/20071017003905/http://wii.ign.com/articles/812/812862p1.html |archive-date=October 17, 2007 |access-date=2008-02-26 |website=IGN}}</ref> The main antagonist of ''Metroid: Other M'', MB, is an android housing an AI cloned from Mother Brain's genetic material from Samus' suit.
===Adam Malkovich=== :{{Voiced by|Rikiya Koyama|Dave Elvin}} Samus' former commanding officer in the Galactic Federation army, he only appears in person in ''Metroid: Other M'', in which he plays a major role. Initially skeptical of accepting her help with his team's mission, he eventually serves as Samus's commander for the duration of the game. The player is unable to use most of Samus' weapons until authorized by Adam at specific points in the game. He usually maintains a calm demeanor, and Samus and Adam are shown to have had a very close relationship, with her seeing him as a surrogate father. Adam is also notable for his commitment to the greater good even at personal cost: in the past he had allowed his brother to pass away in order to avoid risking the deaths of Samus and his team, and upon entering the Sector Zero area of the game, he activates the laboratory's self-destruct protocol, sacrificing himself to save Samus again. In ''Metroid Fusion'', it is revealed that the Navigation Computer of Samus's new ship is Adam Malkovich's consciousness in computer form, although he does not recall this until near the end of the game. This computer consciousness returns in ''Metroid Dread'', albeit impersonated for most of the game by Raven Beak.
===Raven Beak=== :{{Voiced by|Dave Rogers Ruiz}} Raven Beak is the leader of the Mawkin, a Chozo warrior tribe, and the main antagonist of ''Metroid Dread''. He and the Mawkin aided the Thoha, a fellow tribe of the Chozo, in containing the Metroids on SR388, and also gave some of his DNA to Samus. However, after learning that the Thoha intended to destroy the planet to get rid of the Metroids, he murdered them all except one: a scientist named Quiet Robe, whose Thosa control over the Metroids was necessary to use the Metroids as a tool to take over the Galaxy. He is shown to be both cunning and powerful, luring Samus and the Federation to the planet ZDR with footage of X parasites before ambushing and nearly killing Samus. He then pretends to be Adam, putting her through the numerous hardships in her mission to get her to awaken her Metroid powers before asking her to join him near the end of the game. He is ultimately killed by Samus in a final confrontation.
===Metroid Prime / Dark Samus=== '''Metroid Prime''' is the titular main antagonist and final boss of ''Metroid Prime''. Its later form, '''Dark Samus''', is a major antagonist in ''Metroid Prime 2: Echoes'' and the main antagonist of ''Metroid Prime 3: Corruption''. As Metroid Prime, it is a strange, black-carapaced, red-eyed creature with a humanoid face within its shell and the ability to control and horribly mutate anything it attaches to. After its defeat, it reforms itself by stealing Samus' Phazon Suit to become Dark Samus, a black-colored doppelgänger of Samus. Metroid Prime was formed when a Phazon meteor known as a Leviathan impacted on the planet Tallon IV, released its living core, fused with a Metroid.<ref>{{cite video game|title=Metroid Prime|developer=Retro Studios|level=Meteor Strike|quote=Chozo Lore: A meteor came, casting a dark shadow of debris over the land with the violence of its impact. But the meteor brought with it corruption. A Great Poison burst forth into the land, clawing at life with such violence that we were ripped from our peaceful state and find ourselves wandering as shadows of the mortal forms we left behind, searching for why we are here.}}</ref><ref>{{cite video game|title=Metroid Prime|developer=Retro Studios|level=Worm|quote=Chozo Lore: The prophecies tell of the coming of the Worm. Born from parasites, nurtured in a poisoned womb, the Worm grows, devouring from within, until the world begins to rot. The words of the seers have come to pass, for there, in the depths of the world, the ravenous Worm lurks and feeds. From the stars it came, blighting Tallon with its Great Poison. We can but watch as the Worm grows, watch and wait.}}</ref> It caused severe damage to the Chozo colony before the Artifact Temple was built to contain Metroid Prime inside the impact crater of the Leviathan, where it remained until the events of ''Prime'' (although to what degree differs between versions<ref>''Metroid Prime'', NTSC version. '''Space Pirate Data "Metroid Prime":''' Test subject Z-d, hereafter referred to as Metroid Prime, was recently discovered in a cavern by mining crews.</ref><ref>''Metroid Prime'', NTSC version. Space Pirate Data "Prime Breach": Subject Metroid Prime's breach has been contained. Reports indicate that it sensed a large batch of raw Phazon in the lab from within its stasis tank and broke through the glass, using previously unsuspected strength. Besides consuming all of the Phazon, Metroid Prime assimilated several weapons and defense systems from fallen security units.</ref><ref>''Metroid Prime'', PAL version. Space Pirate Data "Impact Crater": Investigations into a possible ingress point for the impact crater continue to meet with failure. The shield of strange energy that protects it is impermeable, and all attempts to tunnel past it have proved fruitless. Our continued futility in this matter is made all the more significant in light of recent life form readings we've discovered emanating from deep within the crater.</ref>). After its defeat, the creature takes Samus' Phazon Suit to reconstruct itself into a body similar to hers, resulting in the being referred to as "Dark Samus".
In ''Metroid Prime 2: Echoes'', Dark Samus arrives on Aether while chasing the planet's Phazon. Shortly after, Samus arrives and encounters Dark Samus many times, eventually defeating her as Dark Aether was destroyed, but a post-credits scene shows Dark Samus reforming herself in deep space.
''Metroid Prime 3: Corruption'' Dark Samus has brainwashed the Space Pirates to be their leader, and begins her mission to spread Phazon across the universe. In an attack to the Galactic Federation vessel G.F.S. Valhalla, Dark Samus steals a supercomputer, the Aurora Unit 313, which is used to implant a computer virus into the Galactic Federation's network of Aurora Units, crippling it. Shortly after, Dark Samus leads an attack on Norion, corrupting Samus and other bounty hunters with Phazon. After Samus destroys the Leviathans of four planets, she goes to Phaaze, where she finally defeats Dark Samus, who then merges itself with the Aurora Unit 313 in a last-ditch effort to defeat Samus. After the Aurora Unit is destroyed, Phaaze explodes, and all Phazon in the galaxy is rendered inert.
Dark Samus appears in ''Super Smash Bros. for Nintendo 3DS and Wii U'' as an Assist Trophy and an alternate costume for Samus. She also appears in ''Super Smash Bros. Ultimate'' with a similar set of moves to Samus, being labeled as an Echo Fighter.
''IGN'' listed Dark Samus as the 88th best video game villain, describing her as being a "creepily evil doppelganger" that never truly dies.<ref>{{Cite web |last=IGN Staff |title=Dark Samus/Sa-X is number 88 |url=http://www.ign.com/videogame-villains/88.html |url-status=dead |archive-url=https://web.archive.org/web/20100509060000/http://www.ign.com/videogame-villains/88.html |archive-date=2010-05-09 |access-date=November 16, 2025 |website=IGN}}</ref> ''TheGamer'' listed her as the 6th best ''Metroid'' character, calling her "one of the most evil and horrifying entities in the series."<ref name="Gamer" /> ''GamesRadar+'' ranked her as being the 4th best fictional evil clone, praising the fact that "[while] evil clones in other games tend to be one-off gimmicks, [she] endured long enough to be the central villain", and stating that unlike "other dark clones [who] just want to bump off their originals, Dark Samus wanted to conquer, and she came awfully damn close – and may come back to do so again".<ref>{{cite web |last=GamesRadar Staff |date=9 January 2012 |title=The Top 7 Evil Clones |url=https://www.gamesradar.com/top-7-evil-clones/2/ |access-date=19 November 2025 |website=GamesRadar+}}</ref>
===Sylux=== :{{voiced by|Laith Wallschleger}}<ref name="prime4va">{{cite web |last=Duwe |first=Scott |date=December 4, 2025 |title=Metroid Prime 4 voice actors – Full voice cast list |url=https://www.destructoid.com/metroid-prime-4-voice-actors-full-voice-cast-list/ |access-date=December 5, 2025 |website=Destructoid}}</ref>
'''Sylux''' is a bounty hunter and former Federation trooper, first appearing as a recurring antagonist in ''Metroid Prime Hunters'' and later as the main antagonist of ''Metroid Prime 4: Beyond''.<ref name="polygonsylux">{{cite web |last=Colantonio |first=Giovanni |title=A brief history of Metroid Prime 4's mysterious villain |url=https://www.polygon.com/metroid-prime-4-beyond-sylux-explained/ |access-date=6 December 2025 |website=Polygon}}</ref> He is considered to be Samus' rival, harboring a great hatred towards her and the Galactic Federation as a whole.<ref>{{Cite web |last=Colantonio |first=Giovanni |date=2021-02-04 |title=Metroid Prime 4's villain has been hiding in plain sight for over a decade |url=https://www.inverse.com/gaming/metroid-prime-4-villain-spoilers-theory-sylux |access-date=2025-11-16 |website=Inverse}}</ref><ref name="polygonsylux" /> His main weapon is the Shock Coil, an electric-based prototype weapon stolen from the Galactic Federation, which drains energy. He can also transform into an alternate form called the Lockjaw, which acts similarly to Samus' Morph Ball, and has a ship named the Delano 7.<ref name="polygonsylux" /><ref name="nlifesylux">{{Cite web |last=Reynolds |first=Ollie |date=5 December 2025 |title=Metroid Prime 4: Beyond - Who Is Sylux? |url=https://www.nintendolife.com/guides/metroid-prime-4-beyond-who-is-sylux |access-date=6 December 2025 |website=Nintendo Life}}</ref> In ''Metroid Prime Hunters'', Sylux and five other bounty hunters try to find the "ultimate power" that is said to be located in the Alimbic Cluster. He and the other bounty hunters battle Samus throughout the game, and are saved by her from Gorea at its end.<ref name="polygonsylux" /><ref name="nlifesylux" /> His spaceship appears in the special ending of ''Metroid Prime 3: Corruption'', which is unlocked after reaching 100% completion, in pursuit of Samus Aran.<ref name="polygonsylux" /><ref name="E3-2015-producer">{{cite news |last=Otero |first=Jose |date=June 16, 2015 |title=E3 2015: What ''Metroid Prime''{{'}}s Producer Wants In the Next Sequel |url=http://www.ign.com/articles/2015/06/17/e3-2015-what-metroid-primes-producer-wants-in-the-next-sequel |url-status=live |archive-url=https://web.archive.org/web/20150930111435/http://www.ign.com/articles/2015/06/17/e3-2015-what-metroid-primes-producer-wants-in-the-next-sequel |archive-date=September 30, 2015 |access-date=September 28, 2015 |website=IGN |publisher=Ziff Davis}}</ref> Sylux also appears in the special ending of ''Metroid Prime: Federation Force'', unlocked if a Metroid egg is rescued in a previous mission, in which he infiltrates a Galactic Federation research station, and releases an infant Metroid from a stasis tube.<ref name="polygonsylux" /><ref>{{Cite web |last=Bailey |first=Dustin |date=2024-06-18 |title=Nintendo has apparently been teasing the big villain of Metroid Prime 4: Beyond for 17 years |url=https://www.gamesradar.com/games/metroid/nintendo-has-apparently-been-teasing-the-big-villain-of-metroid-prime-4-beyond-for-17-years/ |access-date=2025-03-01 |website=GamesRadar |language=en}}</ref>
In ''Metroid Prime 4: Beyond,'' Sylux and the Space Pirates attack a Federation facility holding a mysterious artifact using Metroids, inadvertently activating the artifact, which sends him, Samus, and several Federation soldiers to the planet known as Viewros.<ref>{{cite web |last=Graeber |first=Brendan |display-authors=etal |date=4 December 2025 |title=UTO Research Center Walkthrough |url=https://www.ign.com/wikis/metroid-prime-4-beyond/UTO_Research_Center_Walkthrough |access-date=6 December 2025 |website=IGN |publisher=Ziff Davis}}</ref> Decoys of Sylux are fought throughout the game.<ref name="nlifesylux" /> In visions seen by Samus, it is revealed that Sylux is a former Federation marine and the sole survivor of his platoon after a disastrous mission, in which he wanted to capture a Space Pirate superweapon and recklessly disobeyed his superiors, getting his men killed; Samus then destroyed the superweapon as ordered, making Sylux hate Samus and the Federation.<ref name="nlifesylux" />{{Better source needed|Doesn't mention that Samus destroyed the weapon, a vital part of the backstory|date=December 2025}} After Samus and her Federation allies reach the Master Teleporter on Viewros, Sylux emerges and fights Samus in another dimension, which serves as the final boss fight and ends in his apparent death. As Samus and her friends are about to leave, Sylux returns and damages the Master Teleporter, forcing Samus' comrades to hold him off, seemingly sacrificing themselves so that she can leave the planet before the Master Teleporter stops functioning.<ref name="nlifesylux" /><ref>{{cite web |last=Watts |first=Steve |date=5 December 2025 |title=Metroid Prime 4: Beyond's Ending Does Samus Dirty (Spoilers) |url=https://www.gamespot.com/articles/metroid-prime-4-beyonds-ending-does-samus-dirty-spoilers/1100-6536738/ |access-date=6 December 2025 |website=GameSpot}}</ref>
===Baby Metroid=== The '''Metroid larva''' is chronologically the last Metroid of its race following the events of ''Metroid II: Return of Samus'' and its remake ''Metroid: Samus Returns''. At the beginning of ''Super Metroid'', Samus describes how a Metroid larva hatched from an egg and immediately imprinted upon her, believing her to be its mother. She brought the larva to Ceres Space Colony, where scientists learned that they could harness its power. Just after she left the colony, she received a distress call and returned to find the scientists dead, and the larva stolen. The search for the '''Baby Metroid''' is the source of conflict in the story. When encountered by Samus, the Baby Metroid attacks Samus and nearly drains all her energy. During the final battle against Mother Brain, the Baby Metroid comes to Samus' aid by recharging her energy, but is destroyed by the Mother Brain. Samus avenges its death by destroying Mother Brain with an extremely powerful weapon given to her by the Metroid. After a planet-wide self-destruction, Samus mourns the death of the Metroid. In ''Metroid: Other M'', the Baby Metroid is mentioned in the opening cutscene as it serves as a reminder for Samus' loss of loved ones in her life. Later, on Bottle Ship's Sector Zero, she encounters a Metroid that resembles the Baby Metroid, but it immediately attacks her only to be saved by Adam Malkovich.
''TheGamer'' ranked the Baby Metroid as the 3rd best ''Metroid'' character, calling its sacrifice in ''Super Metroid'' "one of the most emotionally-satisfying moments in the series".<ref name="Gamer" />
==Supporting characters==
=== Kraid === {{nihongo|'''Kraid'''|クレイド|Kureido}} is a gigantic lizard-like beast and as a member of the Space Pirate's High Command. His most prominent feature is his grotesquely oversized belly.<ref name="samus">{{cite web |author=Jesse Schedeen |date=2008-02-12 |title=Stars: Icons — Samus Aran |url=http://stars.ign.com/articles/851/851622p5.html |url-status=live |archive-url=https://web.archive.org/web/20110322181242/http://stars.ign.com/articles/851/851622p5.html |archive-date=2011-03-22 |access-date=2008-02-19 |website=IGN}}</ref> First appearing in the original ''Metroid'', he is the first part of the mini-boss duo along with Ridley.<ref name="timelines">{{cite web |author=<!--Not stated--> |date=October 18, 2002 |title=Metroid Time Line |url=http://gameboy.ign.com/articles/374/374778p1.html |url-status=live |archive-url=https://web.archive.org/web/20110925111347/http://gameboy.ign.com/articles/374/374778p1.html |archive-date=2011-09-25 |access-date=2008-02-26 |website=IGN}}</ref> In ''Super Metroid'', he appears in his giant form, two screens tall and almost a screen wide. ''Metroid: Zero Mission,'' the 2004 remake of the original ''Metroid'', depicts him in a similar size to his appearance in ''Super Metroid''.<ref>{{cite web |author=Craig Harris |date=January 23, 2004 |title=Metroid: Zero Mission |url=http://gameboy.ign.com/articles/474/474827p1.html |url-status=live |archive-url=https://web.archive.org/web/20080720072900/http://gameboy.ign.com/articles/474/474827p1.html |archive-date=2008-07-20 |access-date=2008-02-26 |website=IGN}}</ref> He was also slated to appear in ''Metroid Prime'' as a boss in the Phazon Mines, with a metal dome covering his head and blue Phazon veins on his belly, but was removed due to time constraints.<ref>{{Cite web |last=Walker |first=Ian |date=August 27, 2021 |title=Big Boy Kraid Returns In Metroid Dread |url=https://kotaku.com/big-boy-kraid-returns-in-metroid-dread-1847572506 |access-date=19 November 2025 |website=Kotaku}}</ref> Kraid returns in ''Metroid Dread'' after being captured and experimented on by Raven Beak where he is shown as the first and most significant boss of Cataris, a lava filled zone used to heat the rest of the area he is present in, and is the second boss of the overall game.<ref>{{Cite web |last=Craddock |first=Ryan |date=27 August 2021 |title=Fantastic Metroid Dread Trailer Shows off Frantic Gameplay and a New-Look Kraid |url=https://www.nintendolife.com/news/2021/08/fantastic_metroid_dread_trailer_shows_off_frantic_gameplay_and_a_new-look_kraid |url-status=live |archive-url=https://web.archive.org/web/20210829014058/https://www.nintendolife.com/news/2021/08/fantastic_metroid_dread_trailer_shows_off_frantic_gameplay_and_a_new-look_kraid |archive-date=29 August 2021 |access-date=29 August 2021 |website=Nintendo Life}}</ref><ref>{{cite web |last=Parkin |first=Jeffrey |date=8 October 2021 |title=Kraid boss fight (Cataris) |url=https://www.polygon.com/metroid-dread-guide-walkthrough/22712905/kraid-boss-fight-cataris-boss-battle-tips-tricks |access-date=19 November 2025 |website=Polygon}}</ref> Kraid also makes an appearance in the background of the Brinstar Depths stage in ''Super Smash Bros. Melee'' and ''Super Smash Bros. Ultimate'' where he periodically slashes and rotates the stage.<ref name="Gamer" /><ref>{{cite web |last=Phillips |first=Tom |date=August 27, 2021 |title=Metroid Dread trailer reveals an iconic boss |url=https://www.eurogamer.net/metroid-dread-trailer-reveals-an-iconic-boss |access-date=19 November 2025 |website=Eurogamer}}</ref>
''TheGamer'' listed Kraid as the 7th best character in the ''Metroid'' series, calling him "terrifying", "ruthless", and "iconic".<ref name="Gamer" /> ''Polygon''{{'}}s Michael McWhertor praised the intentionally-added "quick-kill" strategy for Kraid in ''Dread'', which uses bombs—items normally not acquired before Kraid's battle—to drastically reduce the length of the fight, calling it "a fun little reward for ''Metroid'' sequence breakers from developers MercurySteam and Nintendo."<ref>{{cite web |last=McWhertor |first=Michael |date=12 October 2021 |title=Metroid Dread player discovers disgusting shortcut to killing Kraid |url=https://www.polygon.com/22722388/metroid-dread-kill-kraid-easy-sequence-break |access-date=19 November 2025 |website=Polygon}}</ref>
===Etecoons and Dachora=== The Etecoons and Dachora are friendly creatures that Samus encounters on planet Zebes in ''Super Metroid'', and demonstrate to the player how to wall-jump and Shinespark, respectively. At the end of the game during the escape from Zebes, the player can help the Dachora and Etecoons to escape as well by going to an earlier room and blasting open the wall, providing an exit for them. If this is done, they are shown flying off to the right in an escape pod as the planet explodes. They are encountered again in ''Metroid Fusion'' at the Habitation Deck. After releasing them, they find shelter on board Samus's ship. Later on, it is revealed they have a hidden talent with ships, saving Samus's life by piloting her ship during a crucial moment.
The optional saving of the Etecoons and Dachora in ''Super Metroid'' has become a popular element of speedrunning events at GDQ. During the event, viewers are able to either donate money towards "saving the animals", which wastes time, or towards "killing the animals", by escaping normally letting them die off-screen, with the winning option being conducted by the speedrunner. As of early 2017, these donations pulled in nearly $100,000.<ref>{{cite web |last=Mejia |first=Ozzie |title=What is Super Metroid's Save or Kill the Animals incentive? – SGDQ 2021 |website=Shacknews |date=July 10, 2021 |url=https://www.shacknews.com/article/125534/what-is-super-metroids-save-or-kill-the-animals-incentive-sgdq-2021|access-date=7 December 2025}}</ref><ref>{{cite web |last=Washenko |first=Anna |title=What is AGDQ and why should you be watching it? |website=GamesRadar+ |date=January 11, 2017 |url=https://www.gamesradar.com/what-is-agdq-and-why-should-you-be-watching-it/|access-date=7 December 2025}}</ref>
==Species and factions== ===Metroids=== [[File:Metroid (species).png|thumb|upright|Artwork of the larval form of the Metroid species, from ''Metroid: Samus Returns'']] The {{nihongo|'''Metroids'''|メトロイド}} are floating, predatory jellyfish-like organisms with tripartite nuclei and the titular characters of the series. They are capable of siphoning an undetectable life energy from any life form, generally causing Samus's health to rapidly decrease.<ref name="history">{{cite web |author=Rus McLaughlin |date=Jun 15, 2021 |title=IGN Presents The History of Metroid |url=https://www.ign.com/articles/2008/08/15/ign-presents-the-history-of-metroid |archive-url=https://web.archive.org/web/20210428115527/https://www.ign.com/articles/2008/08/15/ign-presents-the-history-of-metroid |archive-date=April 28, 2021 |access-date=Jun 15, 2021 |website=IGN |url-status=live}}</ref> Created by the Chozo as a type of bioweapon in order to combat the more dangerous X Parasites,<ref>{{cite web |last=Whitehead |first=Thomas |date=15 July 2021 |title=New Metroid Dread Report Outlines 7 Points That Define The 2D Saga |website=Nintendo Life|url=https://www.nintendolife.com/news/2021/07/new_metroid_dread_report_outlines_7_points_that_define_the_2d_saga |access-date=19 November 2025}}</ref> they are one of the primary plot points in the ''Metroid'' games as Samus either fights them or tries to prevent the Space Pirates or Galactic Federation from harnessing their powers for evil.
''Metroid II: Return of Samus'' and the remake ''Metroid: Samus Returns'' established a five<!-- Do NOT change this to six. There is no such thing as a Beta Metroid in M2 or Fusion. -->-stage life cycle in which those Metroids native to their home planet SR388 go through two stages of ecdysis followed by two stages of mutation, thus maturing through five previously unknown forms: Alpha Metroid,<!-- Do NOT add Beta here. There is no such thing as a Beta Metroid in M2 or Fusion. --> Gamma Metroid, Zeta Metroid, Omega Metroid, and the uncommon Queen Metroid (the latter as the primary antagonist of the game).<ref name="trailers">{{cite web |author=GameTrailers Staff |date=2007-07-25 |title=The Metroid Retrospective Part 1 |url=http://www.gametrailers.com/video/part-1-the-metroid/22771 |url-status=live |archive-url=https://web.archive.org/web/20100125011615/http://www.gametrailers.com/video/part-1-the-metroid/22771 |archive-date=2010-01-25 |access-date=2008-03-30 |website=GameTrailers}}</ref> They are frequently shown to be vulnerable to ice-based weaponry such as the Ice Beam and freeze guns. These weapons can freeze most Metroids instantly, and often all it takes to finish them off after this is a strong impact such as one from a missile.
''Game Informer'' writer Ben Reevs called the Metroid their favorite alien race in video gaming, praising how their appearance is "truly alien" and that they "pose an immediate and real danger" when they appear.<ref>{{Cite magazine|last=Reevs|first=Ben|url=http://www.gameinformer.com/b/features/archive/2016/05/01/top-10-alien-races.aspx|title=Top 10 Alien Races|magazine=Game Informer|archive-date=2018-01-14|archive-url=https://web.archive.org/web/20180114020308/http://www.gameinformer.com/b/features/archive/2016/05/01/top-10-alien-races.aspx|url-status=live|language=en|date=May 1, 2016|access-date=2018-01-13}}</ref> Kurt Kalata of ''Hardcore Gaming 101'' called their design "iconic", and praised their first appearance in the original ''Metroid'', saying that it was "a moment of shock and terror almost unlike anything in any other NES game", especially if the player did not know how to beat them.<ref>{{Cite news|last=Kalata|first=Kurt|url=http://www.hardcoregaming101.net/metroid/|title=Metroid|date=2017-12-24|work=Hardcore Gaming 101|access-date=2018-01-13|language=en-US|archive-date=2018-01-14|archive-url=https://web.archive.org/web/20180114020207/http://www.hardcoregaming101.net/metroid/|url-status=live}}</ref>
===Space Pirates=== A hostile group known as {{nihongo|'''Space Pirates'''|スペースパイレーツ|Supēsu Pairētsu}}, or {{nihongo|'''Zebesians'''|ゼーベス星人|Zēbesu Seijin}}, serve as the antagonists of the ''Metroid'' series. They are a group of "interstellar nomads" resembling humanoid reptiles, insects, or crustaceans who plunder colonies and ships and exist in an insect-like hive society. Considering their appearance throughout the series, especially the ''Prime'' series, they could be considered arthropod-like reptiles. A single Pirate may have many biological differences from the other individuals of their species, most likely because of their willingness to perform self-experimentation and mutation. Important leaders include Ridley, the Space Pirate commander, Mother Brain, the bio-mechanical defense of Zebes controlled by the Space Pirates, and Kraid, a recurring boss. The organization also includes a winged, mantis-like species, the Ki Hunters. The Space Pirates are interested in Metroid research, especially in using Metroids for energy generation, as soldiers, and for experimentation – their Phazon experiments produced all the Metroid variants seen in the ''Prime'' games with the exception of ''Metroid Prime'' itself. The organization is destroyed during the climax of ''Super Metroid'', but a group within the Galactic Federation itself resurrects the Space Pirates, along with Ridley and the Metroids, to be used as bio-weapons, explaining their continued presence in ''Other M'' and ''Fusion''.
Series director Yoshio Sakamoto stated that the Space Pirates that invaded Zebes took "Zebesian" as a general name for themselves after the conquest of the planet, comparing it to people who referred themselves as "Americans" when they emigrated to the United States.<ref group="‡">{{cite web|url=http://metroid.jp/metroid_version2/development/faq4.html#stage04|title=METROID ZERO MISSION OFFICIAL SITE: Development Room - Metroid FAQ No.31~44|publisher=Nintendo|language=ja|access-date=2012-09-12|quote='''43：大トロイド''' - '''Question:''' スタッフの皆さんに聞きたいことがあります。それは、マガジンZに連載されていたメトロイドの漫画で、スペースパイレーツはもともとゼーベスにいたのではなく、ゼーベスを襲った後、そのまま本拠地にしたはずなのに、何故「ゼーベス星人」と言う名前になってるのでしょか。ぜひ、聞かせてください。 '''Sakamoto:''' アメリカに移住してきた民族が、自らをアメリカ人と呼ぶようなものですね。 / '''43 : Bigtroid''' - '''Question:''' I want to hear from all the staff. In the Magazine Z serialized ''Metroid Manga'', Space Pirates weren't originally from Zebes, and after attacking Zebes, they created their headquarters or main base, why did they call themselves "Zebesians"? Please tell me why. '''Sakamoto:''' It's like how people who have emigrated to America will call themselves Americans.|archive-date=2012-07-29|archive-url=https://web.archive.org/web/20120729031025/http://metroid.jp/metroid_version2/development/faq4.html#stage04|url-status=live}}</ref>
===Chozo=== The '''Chozo''' are a mysterious, birdlike species that are featured throughout the ''Metroid'' series. The origins and age of the Chozo race and civilization are unknown. They were once spread across several planets in the ''Metroid'' universe, notably Elysia, SR388, Tallon IV, Zebes, and ZDR. Lore entries in ''Metroid Prime'' suggest that the race may have traveled to a higher plane of being as opposed to dying out. The sage-like Chozo were extremely advanced in technology, and took pride in their elaborate statuary. They also exchanged knowledge with other species, including the Luminoth of Aether, the Reptilicus of Bryyo, and the Elysians of Elysia (robots which the Chozo themselves built). Lore found in ''Metroid Prime 3'' specifically mentions a fellowship of enlightened races that once existed between the Chozo, the Luminoth and two other species known as the Reptilicus and the Ylla. While the former three have been expounded on in the series, the Ylla are only mentioned in this piece of lore and have yet to be seen.<ref name="AgeofScienceScan">{{cite video game|title=Metroid Prime 3: Corruption|developer=Retro Studios|publisher=Nintendo|date=2007-08-27|platform=Wii|quote=The ships of Bryyo sped to the stars, in all directions, bearing the banner of peace. Soon we found stellar brethren in the Chozo, the Luminoth, and the Ylla. Starborne knowledge came to Bryyo, and we gladly sent our wisdom to our new friends in return.}}</ref> The Chozo were also responsible for raising Samus, infusing her with their DNA and creating her Power Suit, and for the creation and breeding of Metroids to combat the X Parasites.<ref name="trailers" /> While in the Japanese versions of the games, the beings are only ever identified by the generic term {{nihongo|''chōjin-zoku''|鳥人族|lit. "bird-folk race"}}, a misunderstanding during the localization process led to the mistaken adoption of the descriptor {{nihongo|''chōzō''|鳥像|"bird statue"}}, rendered "Chozo", in the English versions instead. In ''Super Metroid'', some of the Chozo statues would rise up and attack Samus; these bosses are called '''Torizo''', substituting the native Japanese word ''tori'' ("bird") for the usual, Chinese-derived ''chō''. In the late game of ''Metroid Prime'' Chozo ghosts appear and attack Samus. Although originally allies, the Chozo became maddened by the Phazon corruption of their planet, and could no longer distinguish friend from foe. In ''Metroid Zero Mission'', Samus is able to enter the Chozo Ruins.
In ''Metroid Dread'', the social structure of the Chozo is explored, revealing they are split into two tribes: the peaceful '''Thoha''', who left their warrior traditions behind to become scientists, and the '''Mawkin''', who retained a warrior culture. The Thoha initially colonized SR388 and encountered the X parasites, genetically engineering the Metroids to serve as their predators. For this reason, the Metroids are calm in the presence of Thoha genes and hostile towards Mawkin. While the Thoha feared both species, the leader of the Mawkin, '''Raven Beak''' (who is a biological donor to Samus), saw potential in the Metroids, and ordered the killing of all but one Thoha ('''Quiet Robe''') so they would not obstruct his plans. One Mawkin soldier, however, was infected with an X while returning to ZDR and a pandemic broke out, leaving Raven Beak and Quiet Robe the only known living Chozo when ''Metroid Dread'' takes place. Since they are both killed during the game, the Chozo are believed to be extinct as of ''Dread''.
In the ''Metroid'' manga series, which is a prequel to the original game, two Chozo who had a hand in Samus's origins were introduced as '''Old Bird''' and '''Gray Voice'''. When Samus lost her family to the Space Pirates, they took her under their wings and raised her to become the galactic savior she is today, and Gray Voice was one of the Chozo who donated his DNA to Samus. Gray Voice later feigned joining the Space Pirates in an attempt to destroy the renegade Mother Brain.
===Galactic Federation=== The {{nihongo|'''Galactic Federation'''|銀河連邦|Ginga Renpō}} is the governing body of the galaxy formed by an alliance of alien species<ref>{{cite web |title=Metroid eManga pgs. 9-11 |url=http://www.mechadrake.com/metroidmanga.html |url-status=live |archive-url=https://web.archive.org/web/20181003095747/http://www.mechadrake.com/metroidmanga.html |archive-date=2018-10-03 |access-date=2007-10-18}}</ref> and often contracts Samus with difficult missions to complete, which typically make up the majority of the games. Samus trained in the Federation's military before becoming a bounty hunter, leaving some time after a disagreement with her commanding officer, Adam Malkovich in the events of ''Metroid: Other M''.<ref name="FusionAdamDiscussion">{{cite video game|title=Metroid Fusion|developer=Nintendo R&D1|publisher=Nintendo|date=2002-11-15|platform=Game Boy Advance|quote='''Computer:''' Did this "Adam" care for you? Would he sit in a safe Command Room and order you to die? / '''Samus:''' He would understand that some must live and some must die… He knew what it meant. He made that sacrifice once. / '''Computer:''' So he chose life for you? Our fair warrior, Samus Aran… Your Adam gave his life so that you might keep yours… For the sake of the universe…}}</ref> The Galactic Federation's troopers also use powered armor, and their technology usually bears multiple versions of their symbol, a stylized cross-shape. Troopers are also given a basic repeating assault weapon, and in ''Metroid Prime 3'', some are equipped with the Phazon Enhancement Device.
===Ing Horde=== The Ing Horde is a race of powerful and intelligent dark creatures appearing in ''Metroid Prime 2: Echoes''. They are capable of possessing anything organic, mechanical, artificial, dead, or alive (including the Metroids).
They originated when a Leviathan from Phaaze impacted the planet Aether and created Dark Aether, a trans-dimensional duplicate of the planet. The Ing then fight against the Luminoth in a decades-long war over the Light of Aether, and appear to be on the verge of victory until Samus comes to Aether looking for a missing Galactic Federation squadron and fights against the Ing. She recovers the missing energy using an Energy Transfer Module that the Ing took from the Luminoth, and eventually defeats the Emperor Ing, destroying Dark Aether and the Ing for good.
===X Parasites=== The '''X Parasite''' is a unique parasite witnessed in ''Metroid Fusion'', ''Metroid: Samus Returns'', ''Metroid Dread'' and the ''Metroid'' manga. They are the main antagonistic force of ''Fusion''.
The appearance of an X Parasite is simple: a basketball-sized, floating gelatinous life form. The structure of their bodies allow them to slip through the tiniest crevices of any organism or synthetic surface; their soft form also allows projectiles to harmlessly pass through them. Additionally, they have the ability to split into smaller colonies via asexual reproduction.
X are capable of infecting other organisms and mimicking their prey's DNA and memories. They do this by infecting the organism's nervous system where they then start reproducing at an exponential rate, killing the host creature in the process. Once that is accomplished, the X absorbs the DNA of their host and is then able to use it to mimic their prey perfectly. X can also mimic biomechanical technology, such as the Security Robot B.O.X. and Samus' Power Suit, codenamed '''SA-X''', which serves as the main antagonist of ''Fusion''.
The final X Parasites are contained in Elun on the planet ZDR, and midway through ''Metroid Dread'' are released by Raven Beak to hinder Samus. The bosses Escue, Golzuna, Experiment No. Z-57, as well as the Chozo Soldiers, are all X, and Raven Beak himself is infected by an X after being defeated by Samus. The detonation of ZDR at the game's finale presumably marks their extinction.
=== The Lamorn === The '''Lamorn''' are an extinct tentacled humanoid race first appearing in Metroid Prime 4.
==Reception== ''TheGamer'' praised the series' "fascinating selection of Bounty Hunters, antagonists, and old acquaintances", noting their "intriguing backstories and personalities."<ref name="Gamer">{{cite web |last=Chamaillard |first=Kyle |date=13 June 2023 |title=Metroid: Best Characters |url=https://www.thegamer.com/best-metroid-characters/ |website=TheGamer |access-date=19 November 2025}}</ref>
==Notes== {{Reflist|group=lower-alpha}}
==References== {{Reflist}} {{Primary sources reflist}}
{{Metroid series|state=expanded}}
Metroid * Metroids