Rahi
Biomechanical Fauna of the Matoran Universe
The Rahi were the biomechanical wildlife of the Matoran Universe, built largely by the Brotherhood of Makuta, ranging from background fauna to engineered war beasts.

Rahi were the biomechanical fauna of the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control.. The word itself meant "not us" in MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body., distinguishing instinct-driven wildlife from the sapient species that inhabited the universe. Most Rahi were manufactured by the Brotherhood of MakutaMakuta (Species)Shadowy Antidermis beings and the Brotherhood's elite, Makuta commanded darkness and shaped the Matoran Universe's fate., blending viruses with liquid ProtodermisProtodermisThe engineered substance building the Matoran Universe, protodermis exists in countless refined states from mundane metal to diamond-hard crystal to the destruction-or-transformation force of energized form. in vats, though some lineages predated the Brotherhood and were attributed to the Great BeingsThe Great BeingsScholar-inventors of Spherus Magna whose creations shaped the Matoran Universe and whose absence defined the conflicts that followed. or the Hand of ArtakhaArtakhaArtakha is the master craftsman of the Matoran Universe, ruler of a hidden island where the Toa Mata came into being and the Avohkii was forged..
Definition#
The term Rahi in the MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. language meant "not us" and described any non-sapient biomechanical lifeform within the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control.. The distinction was not strictly behavioral but biological. Sapient beings such as MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body., Toa, and TuragaTuragaFormer Toa who fulfilled their destiny and transformed into leaders. Turaga wield Noble Kanohi masks and weakened elemental powers, guiding their communities. carried significant inner Light, while Rahi possessed only minimal amounts, sufficient for detection or drainage but insufficient for moral reasoning. As a result, Rahi acted on instinct rather than purpose, driven by hunger, territoriality, or programmed behavior.
Rahi anatomy combined organic tissue with ProtodermisProtodermisThe engineered substance building the Matoran Universe, protodermis exists in countless refined states from mundane metal to diamond-hard crystal to the destruction-or-transformation force of energized form.-based structural elements. Most species were specialized for a single ecological niche, with body plans tuned to aerial, aquatic, terrestrial, or subterranean environments. They could be trained, deployed as weapons, or used for communication and reconnaissance, but were treated by the dominant species as tools rather than agents. The Dark HuntersThe Dark HuntersA band of mercenaries and thieves founded on Odina by the Shadowed One and Ancient, hired out across the Matoran Universe, and left a battered ruin by the time Teridax ruled the universe., for example, used bat-winged Rahi bred for long-distance flight as messengers, while the Brotherhood of MakutaMakuta (Species)Shadowy Antidermis beings and the Brotherhood's elite, Makuta commanded darkness and shaped the Matoran Universe's fate. maintained whole classes of war Rahi for direct combat.
Origins and Creators#
The Brotherhood of MakutaMakuta (Species)Shadowy Antidermis beings and the Brotherhood's elite, Makuta commanded darkness and shaped the Matoran Universe's fate. was responsible for the majority of Rahi species in the universe. Production took place in large vats where viruses were combined with liquid ProtodermisProtodermisThe engineered substance building the Matoran Universe, protodermis exists in countless refined states from mundane metal to diamond-hard crystal to the destruction-or-transformation force of energized form., allowing the Brotherhood to design creatures for specific ecological or military roles. The KardasKardasA winged Rahi dragon created when the Mask of Life rebuilt the Fenrakk spider in the lava of the Chamber of Life, with Vezon still fused to its back. Dragon, the VisorakVisorak (Rahi)Spider-like Rahi employed by the Brotherhood of Makuta whose name meant 'Stealers of Life' and whose swarms threatened the Matoran Universe. breeds, and various war Rahi deployed under TeridaxTeridaxTeridax orchestrated a thousand-year scheme that ended with him occupying the Great Spirit Robot itself before his death on Bara Magna.'s direction all originated from this process.
Older Rahi predated the Brotherhood. The Great BeingsThe Great BeingsScholar-inventors of Spherus Magna whose creations shaped the Matoran Universe and whose absence defined the conflicts that followed. created several early species during the construction phase of the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control., and the Hand of ArtakhaArtakhaArtakha is the master craftsman of the Matoran Universe, ruler of a hidden island where the Toa Mata came into being and the Avohkii was forged. was credited with engineering guardian Rahi tied to defensive and restorative roles. The ArtakhaArtakhaArtakha is the master craftsman of the Matoran Universe, ruler of a hidden island where the Toa Mata came into being and the Avohkii was forged. Bull and similar species are believed to belong to this older lineage, though full attribution is incomplete in surviving records.
Subsequent mutations were driven by exposure to Energized ProtodermisEnergized ProtodermisA sentient substance that could remake or annihilate any being that touched it. One of the Matoran Universe's most lethal hazards.. The substance changed what already existed rather than making anything new, reworking Rahi into different forms whenever contact occurred. Documented examples include the Hordika Dragons and the altered Bog Snakes of the Swamp of SecretsSwamp of SecretsThe Swamp of Secrets was the mutagen-saturated wetland that filled the floor of Karda Nui after the Great Cataclysm, serving as a Brotherhood stronghold until the Energy Storms.. HelryxHelryx: the first Toa ever createdHelryx was the first Toa ever made, commissioned by the Great Beings on Artakha long before the Toa Mata. She founded and led the Order of Mata Nui. recorded the existence of a lake of energized ProtodermisProtodermisThe engineered substance building the Matoran Universe, protodermis exists in countless refined states from mundane metal to diamond-hard crystal to the destruction-or-transformation force of energized form. capable of producing partially formed living matter on its own, demonstrating that the substance could generate as well as transform.
Rahi in Major Regions#

Within Metru NuiMetru NuiThe city beneath Mata Nui functions as the Great Spirit's brain, housing the Matoran whose labor keeps the god alive., Rahi populations were concentrated in the Archives, the deep complex maintained by the Onu-MatoranOnu-MatoranEarth-wielding Matoran of the deep who adapted to darkness and built the Matoran Universe's defensive cavalry. that housed thousands of preserved and active specimens. After incidents such as the KardasKardasA winged Rahi dragon created when the Mask of Life rebuilt the Fenrakk spider in the lava of the Chamber of Life, with Vezon still fused to its back. Dragon breakout, most loose Rahi were returned to secure containment. The Archives functioned as both a biological library and a strategic reserve, holding species drawn from across the universe.
In Karda NuiKarda NuiThe vast cavern at the core of the Matoran universe, home of the Av-Matoran's Sky Villages and the Codrex, and the site of the battle to awaken Mata Nui., the post-Cataclysm flooding of the dome floor produced the Swamp of SecretsSwamp of SecretsThe Swamp of Secrets was the mutagen-saturated wetland that filled the floor of Karda Nui after the Great Cataclysm, serving as a Brotherhood stronghold until the Energy Storms., a toxic environment populated by Rahi that had either adapted to or been mutated by the Pit MutagenMutagenPit Mutagen was a power-source energy that leaked into the waters of The Pit during the Great Cataclysm and mutated almost every being exposed to it.. The Brotherhood maintained an active presence in the swamp, and several known Brotherhood-created Rahi, including the Nui-KopenNui-KopenGiant wasp Rahi that Le-Matoran tamed for travel, but they're far more dangerous when controlled by Toa., NiazeskNiazeskEngineered by Makuta Bitil to keep larger Rahi in check, the Niazesk got one brief, mutated outing in Karda Nui before the Energy Storms wiped them out., and Swamp Stalkers, were stationed there to guard the CodrexThe CodrexA spherical vault built by the Great Beings in Karda Nui, where the Toa Mata slept in their canisters and where Mata Nui's reawakening was finally set off. and adjacent strategic sites.
On the Southern Continent, Rahi populations included territorial and integrated species such as the plant-aligned guardians encountered by MazekaMazekaA Ko-Matoran spy for the Order of Mata Nui obsessed with becoming the perfect warrior. during his expeditions. The Dark HuntersThe Dark HuntersA band of mercenaries and thieves founded on Odina by the Shadowed One and Ancient, hired out across the Matoran Universe, and left a battered ruin by the time Teridax ruled the universe. maintained breeding programs for specialized roles, particularly the long-distance bat-winged messenger Rahi used in their communications network.
Designs and Behavior#
Rahi bodies were equipped with biological tools suited to predation, defense, or environmental specialization. Pincers, stingers, claws, and reinforced armor were common across species, with variations driven by habitat. Aquatic Rahi were observed tearing through ZyglakZyglakZyglak are a species of dark red, dark blue, and white creatures who are amphibious and wield spears and knives in combat. Formerly confined to the Pit, the Zyglak now inhabit Spherus Magna. vessels using powerful clawed limbs, and large terrestrial species such as the MuakaMuakaTiger-like predators of Ko-Wahi with claws, teeth, and a taste for anything that moves. and Kane-RaKane-RaBuffalo-like territorial Rahi that roamed Mata Nui's plains and Metru Nui's corridors, best known for encounters with the Toa. were built for sustained combat and pack or solitary hunting.
Behaviorally, Rahi reacted rather than reasoned. Their actions followed instinct, training, or, in the case of Brotherhood-created species, embedded behavioral programming. Bat-winged Rahi delivered messages because they were bred to do so, without external direction beyond a basic trigger. RahkshiBionicle Rahkshi: the Sons of Makuta from Mask of LightRahkshi are armoured hunters made from kraata, the slug-like creatures of the Makuta. Six of them chased the Mask of Light across Mata Nui in 2003. Here's what they are, the different kinds and where they turn up in the films, books and comics., produced through the use of energized ProtodermisProtodermisThe engineered substance building the Matoran Universe, protodermis exists in countless refined states from mundane metal to diamond-hard crystal to the destruction-or-transformation force of energized form. on kraata, occupied a related category of designed creatures meant to hunt and destroy without hesitation.
The minimal inner Light carried by Rahi reinforced their dependence on external direction. They were detectable and drainable by entities such as Shadow LeechesShadow LeechMutated Kraata designed to drain light and corruption. Created by Mutran and allies, they transformed dozens of Matoran before the Energy Storm wiped them out., but their behavior could not be altered through moral or rational appeal. This characteristic made them suitable as ecological background, biological infrastructure, or expendable combat assets, depending on the user.
Engineered War Rahi#
The Brotherhood's later Rahi designs were increasingly oriented toward warfare rather than ecology. The VisorakVisorak (Rahi)Spider-like Rahi employed by the Brotherhood of Makuta whose name meant 'Stealers of Life' and whose swarms threatened the Matoran Universe. breeds were the most prominent example, engineered to conquer entire regions through coordinated swarming tactics, paralytic venom, and command structures sustained by SidorakSidorakHe took credit for someone else's idea, called it leadership, and spent his whole reign as the Visorak's king certain he could not be out-played., RoodakaRoodakaShe spent the entire Visorak arc letting everyone think they were using her, then walked away having beaten the Brotherhood and the Toa at their own game., and the Heart of the VisorakHeart of the VisorakA golden crystal that compels every Visorak in the universe to converge on its location when activated.. The Heart allowed the VisorakVisorak (Rahi)Spider-like Rahi employed by the Brotherhood of Makuta whose name meant 'Stealers of Life' and whose swarms threatened the Matoran Universe. to be summoned from any point in the universe, functioning as a remote mobilization tool.
Nui-KopenNui-KopenGiant wasp Rahi that Le-Matoran tamed for travel, but they're far more dangerous when controlled by Toa., NiazeskNiazeskEngineered by Makuta Bitil to keep larger Rahi in check, the Niazesk got one brief, mutated outing in Karda Nui before the Energy Storms wiped them out., and the Swamp Stalkers of the CodrexThe CodrexA spherical vault built by the Great Beings in Karda Nui, where the Toa Mata slept in their canisters and where Mata Nui's reawakening was finally set off. region represented dedicated guardian species. Unlike opportunistic predators, they were deployed to specific zones, displayed coordinated aggression, and functioned as part of layered defense networks around high-value sites. War Rahi were also kept in the service of individual Brotherhood members, including the dragon-class Rahi recorded as tracking TeridaxTeridaxTeridax orchestrated a thousand-year scheme that ended with him occupying the Great Spirit Robot itself before his death on Bara Magna. on SteltSteltAn island in the Matoran Universe known for producing ruthless warriors like Sidorak and Krekka., a creature BrutakaBrutakaBrutaka guarded the Kanohi Ignika on Voya Nui, betrayed the Order during the Piraka incursion, was mutated in the Pit, and later led the Order's strike team to free Miserix. identified as an "old war Rahi" from his own experience.
KeetonguKeetonguThe legendary Rahi who broke the Visorak siege and lived to prove he was worth the legend., a Rahi species capable of curing VisorakVisorakSpider-like Rahi created by Makuta Chirox, conquered for the Brotherhood by Gorast, broken at Metru Nui, and ultimately destroyed in a volcanic eruption on Artidax. venom, occupied a counterposed role. His combat record during the Destiny WarThe Destiny WarThe open war between the Order of Mata Nui and the Brotherhood of Makuta, told in the 2008 Destiny War podcast, which ended with the Brotherhood's assault on Metru Nui broken and the Great Spirit apparently awake. confirmed that anti-Rahi capabilities existed within the Rahi population itself, though the rarity of his species limited the practical scope of that countermeasure.
Intelligence and Edge Cases#
Most Rahi displayed instinctual rather than reasoned behavior, but several species sat at the border of that classification. The Archives BeastThe Archives BeastA shapeshifting Rahi locked away in the lower levels of the Archives, which disguised itself as an empty room and was driven off by cold., housed in Metru NuiMetru NuiThe city beneath Mata Nui functions as the Great Spirit's brain, housing the Matoran whose labor keeps the god alive., demonstrated guarded territorial behavior that suggested defensive conditioning rather than simple aggression. TakuaTakuaAn Av-Matoran hidden on Mata Nui as a Ta-Matoran, who gathered the Toa Stones, served as Chronicler, and ultimately accepted the Avohkii to become Takanuva, the Toa of Light. narrowly escaped it during his time in the city, and AxonnAxonnAxonn served as an arbitrator under the Hand of Artakha and later as an Order of Mata Nui agent, guarding the Kanohi Ignika on Voya Nui for thousands of years.'s combat record indicated that even experienced fighters treated it as a serious threat.
The dragon-class war Rahi referenced by BrutakaBrutakaBrutaka guarded the Kanohi Ignika on Voya Nui, betrayed the Order during the Piraka incursion, was mutated in the Pit, and later led the Order's strike team to free Miserix. likewise indicated trained military assets with retained operational memory across long service intervals. Bat-winged Rahi bred for communication carried out structured tasks with minimal direct supervision. These cases complicated the simple framing of Rahi as wildlife. The classification remained primarily one of inner Light and sapience rather than capability, with creatures bred for loyalty or defense operating closer to trained agents than to truly wild fauna.
Migration to Spherus Magna#
When the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control.'s systems collapsed following the awakening of the Great Spirit Mata NuiMata NuiBuilt by the Great Beings to restore Spherus Magna, Mata Nui sustained an entire civilisation inside his body, was deposed by Teridax, and reclaimed his purpose as a mortal on Bara Magna., most surviving Rahi migrated to the reformed Spherus MagnaSpherus MagnaA desert world of ancient conflict that became the merger point of the Matoran Universe and Bionicle's true endpoint.. The adaptability that had been built into them, by Brotherhood design, mutagen exposure, or natural ProtodermisProtodermisThe engineered substance building the Matoran Universe, protodermis exists in countless refined states from mundane metal to diamond-hard crystal to the destruction-or-transformation force of energized form.-based biology, allowed them to integrate into the planet's reformed ecosystems alongside the native fauna observed by Toa, AgoriAgoriThe villager species of Bara Magna, organised by tribe and settlement, who governed their villages and lived by the Glatorian arena system., and other survivors.
The Rahi on Spherus MagnaSpherus MagnaA desert world of ancient conflict that became the merger point of the Matoran Universe and Bionicle's true endpoint. functioned as living remnants of the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control.. Their biomechanical composition distinguished them visibly from the planet's organic native species, and bat-winged messenger Rahi and similar engineered breeds persisted as evidence of a wholly designed biology now operating in a natural setting. The Rahi outlasted the empires that had built or contained them, and remained a stable population on the restored world.
Frequently asked questions
- What are Rahi in BIONICLE?
- Rahi were the biomechanical fauna of the Matoran Universe, with the word itself meaning "not us" in the Matoran language, distinguishing instinct-driven wildlife from sapient species. They possessed only minimal inner Light and acted on instinct rather than moral reasoning.
- Who created the Rahi?
- Most Rahi were manufactured by the Brotherhood of Makuta, who combined viruses with liquid Protodermis in large vats to design creatures for specific ecological or military roles. Older lineages predated the Brotherhood and were attributed to the Great Beings or the Hand of Artakha.
- How were Rahi used as weapons?
- Rahi were treated as tools rather than agents and could be trained, deployed in combat, or used for surveillance and communication. The Dark Hunters used bat-winged Rahi bred for long-distance flight as messengers, while the Brotherhood maintained whole classes of war Rahi, including the Visorak breeds engineered to conquer entire regions.
- What happened to the Rahi after the Matoran Universe collapsed?
- When the Matoran Universe's systems collapsed following the awakening of Mata Nui, most surviving Rahi migrated to the reformed Spherus Magna. Their built-in adaptability allowed them to integrate into the planet's reformed ecosystems alongside the native fauna, outlasting the empires that had built or contained them.
- How did Energized Protodermis affect Rahi?
- Energized Protodermis acted as a transformative agent that reshaped existing Rahi into new forms upon contact, producing examples such as the Hordika Dragons and the altered Bog Snakes of the Swamp of Secrets. Helryx recorded that a lake of energized Protodermis could even generate partially formed living matter on its own.
Gallery


Images via BIONICLE Wiki (Biosector01)
Sources
- SerialDestiny War, Primary source via BS01 wiki entry
- SerialFederation of Fear, Primary source via BS01 wiki entry
- SerialReign of Shadows, Primary source via BS01 wiki entry
- SerialSwamp of Secrets, Primary source via BS01 wiki entry
- SerialThe Mutran Chronicles, Primary source via BS01 wiki entry
- WikiRahi, BS01 character/subject entry
Spotted a factual error or a primary source we missed? Email a correction. Every flagged claim gets reviewed.
Followed from this entry

Niazesk
Engineered by Makuta Bitil to keep larger Rahi in check, the Niazesk got one brief, mutated outing in Karda Nui before the Energy Storms wiped them out.

Visorak
Spider-like Rahi created by Makuta Chirox, conquered for the Brotherhood by Gorast, broken at Metru Nui, and ultimately destroyed in a volcanic eruption on Artidax.
The Archives Beast
A shapeshifting Rahi locked away in the lower levels of the Archives, which disguised itself as an empty room and was driven off by cold.

Keetongu
The legendary Rahi who broke the Visorak siege and lived to prove he was worth the legend.

Mata Nui
Built by the Great Beings to restore Spherus Magna, Mata Nui sustained an entire civilisation inside his body, was deposed by Teridax, and reclaimed his purpose as a mortal on Bara Magna.

Teridax
Teridax orchestrated a thousand-year scheme that ended with him occupying the Great Spirit Robot itself before his death on Bara Magna.
Mentioned in414 entries
300-foot Venom Eel
A Venom Eel mutated to colossal size by the defensive reaction of the Ignika, active in the waters around Mahri Nui during the search for the Mask of Life.
Airship
Airships were flying cargo vessels used across the Matoran Universe, based in Metru Nui at the Le-Metru Moto Hub and flown by skilled Le-Matoran pilots using Kanoka and pressurized protodermis for lift and thrust.
Airweed
The underwater plant of the Fields of Air whose bubbles let the Matoran of Mahri Nui breathe beneath the sea.
Amana Volo Sphere
Amana Volo Spheres are rare globes of energy released by certain Rahi when their Infected Kanohi are removed, absorbed to restore health and boost strength, and handed to Takua as rewards in the game Quest for the Toa.
Archives Mole
Small, harmless burrowing Rahi engineered by the Makuta, originally native to Po-Metru and forced into the shadowy recesses of the Onu-Metru Archives, where their cooperative behaviour built living ladders and bridges through the lower levels.
Artakha Bull
The Artakha Bull was a hostile, bull-like Rahi of Le-Metru, unusually intelligent for its kind and so hard to capture. Legend held that its cunning was why it shared its name with the hidden land of Artakha.
Artidax
Artidax was a volcanic island in the southern islands where Makuta Krika imprisoned Miserix instead of killing him, and where the Visorak horde later met its end.
Ash Bear
A powerful bear-like Rahi created by the Makuta, two to three times the size of a Matoran, kept in the Archives of Metru Nui and best known through Graalok, the territorial bear of Le-Wahi.
Assembler's Village
Assemblers' villages were small, isolated Po-Matoran workshop settlements in Po-Metru where crafters assembled Matoran goods and tools from parts shipped across the city.
Avohkah
The Avohkah were incredibly fast and powerful elemental beings, sentient lightning bolts produced as by-products of the Av-Matoran's labours in Karda Nui and defeated by the Toa Mata before the Great Spirit Mata Nui's awakening.
Axonn
Axonn served as an arbitrator under the Hand of Artakha and later as an Order of Mata Nui agent, guarding the Kanohi Ignika on Voya Nui for thousands of years.
Badge of Office
The Badge of Office was the staff or tool carried by a Turaga to symbolize experience and authority, most often the transformed Toa Tool the elder had wielded in their days as a Toa.
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