To Build a Toa (or Matoran)

Some artwork, a lot of theorizing, and a big essay… basically, this is my distilled thoughts on how a Toa (or more likely a Matoran, but I used my Toa Lis as a model) would be built. Enjoy.

1 – The Frame

One starts with the frame: the bare skeleton. Toa and Matoran bones are inorganic, made of metal. Compared to a human skeleton, several major differences are apparent: first, Toa lack a ribcage or similar structure, featuring only a sternum with hole in the middle for the fitting of the heartlight. The second is the structure of the spine; a spine is the core of a Toa or Matoran’s body, composed of ten tubular sections (vertebrae) connected by ball joints. Each vertebra is fitted with a large metal ring; these rings will form the outer frame of the spinal assembly later on. The #1, #4, #7, and #10 vertebrae (counting from the top) are of particular interest: #1 is bolted to the base of the skull (and hidden by the skull from most angles), #4 is fitted with hinges to which the shoulder cups attach and two rings that wrap around the shoulder cups to connect to the top of the sternum, #7 is fitted with a small inner ring for the spinal assembly and a large outer ring that connects to the base of the sternum, and #10 is significantly wider than the others and connects to the hip assembly. The spine, though strong, is extraordinarily flexible; when not fitted with dampening pistons or other obstructions in the waist area, a Toa or Matoran can turn their upper body just over 90 degrees to the left and right without moving their hips at all.

Besides featuring prominently in the spine, ball joints are also used in the shoulders, hips, and in the fitting of the hands and feet, enabling a wide range of movement for the limbs. The knees and elbows use simpler hinge joints. Both hands and feet only consist of a core piece at this point: the palm for the hands and the heel for the feet, still lacking digits. Though the limbs are nearly identical in construction in everything other than scale and appendage, of note is that the lower leg construction features an additional two bones. These are usually not load-bearing, but serve to limit the range of movement of the feet to prevent injury of the ankle joints. Some Toa will have a similar assembly fitted to their lower arms to bolster the wrist joints for use of heavy weapons, but this not included in the standard build. Proportions can vary based on need as well; Toa of Earth are routinely constructed with larger upper bodies and arms to help in digging, while Toa of Water are made slightly slimmer in the shoulder area and with stronger legs to be more streamlined and powerful swimmers (coincidentally mimicking the body proportions of a female Glatorian to some degree; it has been speculated that this resemblance led the great beings to make Toa and Matoran of water female).

Also notable are the ‘nodes’ fitted on key points of all the bones: these are anchor points for the reservoirs and muscle strands to be attached later on. They also feature conduits leading into the hollow center-section of each bone; a Toa’s circulatory system, which provides both nutrients and oxygen to the muscle strands and reservoirs, is internal to their skeleton. Before the frame is fitted with reservoirs and muscle strands, the flexible tubes that connect these hollow sections through the joints to produce a water-tight circulatory system are also the only thing that holds it all together. Nerve strands, thin copper wires connected to the brain that can carry electrical signals that tell muscle strands to contract, are also fitted internally with these tubes. By nature, most of the nodes are found close to the joints that the muscle strands they will feed need to move.

Lastly, the skull is constructed of several pieces: the braincase, an upper and lower jaw, a hinge to connect the two, and a reinforcing structure. The braincase is boxy in shape, features two holes in the front for the eyes, and is connected to the #1 vertebra at the lower back, becoming the base for the whole skull in the process. The upper jaw and hinge are fitted straight to brackets incorporated into the bottom of the brain case, with the lower jaw fitted to the hinge in turn. The reinforcing structure consists of thicker metal plates that are fitted around the eye sockets and forehead. It features connection points for a kanohi and is designed to absorb most of the impact of any blow to the head through these points. Lastly, the jaws are fitted with teeth. Toa and Matoran only need to eat rarely if they have access to a regular electrical (or rarely elemental) recharge point; eating more often makes the teeth prone to corrosion, making periodic re-fitting and polishing a necessity. Due to this additional maintenance, Toa, Matoran, and other beings in the Matoran Universe with the exception of the Skakdi disliked eating.

2 – Core Organs and Brain

The organs needed to keep both the electrical and organic parts of the body working are fitted next. First comes the completion of the spine assembly: a single digestive tract, running from the back of the mouth to the base of the spine, is fitted anterior to the spine. Once the Toa or Matoran is activated, the tract will partially fill with a highly acidic substance capable of breaking down any organic material and a fair number of metals, too, turning them into a slurry of organic molecules that, when diluted into the bloodstream, drives the healing and refreshing of both muscle strands and reservoirs. Metals are broken down into microscopic fragments that remain suspended in the bloodstream until they are needed to fix a broken bone. Though it has an entrance in the mouth, the digestive tract of a Toa, Matoran, or many other related beings in the Matoran Universe does not have an exit; in the event that a Toa consumes something that they cannot digest (even though they have, on average, a month between meals to do so), the only way that they can get rid of it is to vomit it back up.

A reservoir is wrapped around the digestive tract and spinal column, filling the rest of the space between them and the spinal assembly’s outer rings and insulating both from extreme temperatures. Lastly, a thick fabric composed of layers upon layers of thin, bare muscle strands known as flexweave is stretched between the rings and attached to their insides to both cover and protect everything within the spinal assembly and to make the assembly mobile; the final result can move like a snake but is more rigid to support the weight of everything attached around the chest and shoulder area. Since spinal assembly, when completed, is able to take in energy through the digestive tract and store it in the reservoir and the flexweave can absorb oxygen from air, a Toa head and spinal assembly can be kept alive entirely on their own without anything else attached if need be (pit mutagen reduced the Piraka to nothing but their heads and spines, and they still lived by the same mechanism).

Once the spinal assembly is completed, a respiration system is fitted between the sternum and the spinal assembly. Its core is the heart pump, fitted right behind the sternum for protection. It pumps blood from the circulatory system through the air exchangers, oxygenizing it to supply all the organic components of the Toa’s body. Fitted with the pump is the heartlight, which indicates the pump is running by pulsing at a rate proportional to the pump’s current RPM. An irregular or absent beat of the heartlight therefore indicates problems with the pump, which need to be addressed quickly; if the pump stops, so does the oxygen supply to the reservoirs and the muscle strands, rendering a Toa immobile within about two hours (even then, it would likely take at least a week before they would die by dehydration or even longer by starvation). The air exchangers fill most of the chest and look like sacs of a tightly woven, metallic fabric, but inside they look more like radiators, filled with permeable blood vessels that absorb oxygen from the air into the bloodstream while expelling gaseous or liquid waste from the muscle strands as vapor. They incorporate muscle strands that alternately contract the top and bottom of the air exhangers, pumping fresh air through them and allowing the Toa to breathe.

Since the only way to fit them is through the back of the skull, a Toa’s eyes are fitted into their head before their brain is. The eyes are intricate cameras, assembled as units that contain an adjustable lens for focus and very limited telescopic vision and are fitted inside of a thin, spherical protective casing. Small muscle strands stretched between this casing and nodes on the inside of the skull allow the eyes to move and point in different directions, though they usually move in tandem. After the eyes are fitted, the brain follows. A Toa’s brain is a very pure crystal, whose atoms or molecules make up a matrix that works like a neural network, receiving, processing, and sending out electrical pulses. It’s got contact nodes on the front that connect to the eyes and a large one on its base that connects with the neural network and a power cable coming up from the spinal assembly. Rubber or similar shock absorbers are fitted between the brain and its case to ensure a blow to the case does not damage the hard but brittle brain.

Also fitted on the head is a lower facial cover; a thin metal structure that fits tightly around the jaw assembly and incorporates a thick protective ring around the mouth. It also incorporates a set of thin metal plates that close to form a mouth in front of the teeth and can be bent by muscles behind them to allow the mouth to make some simple expressions. The lower facial cover prevents scraps of food from spilling out of the mouth when the Toa eats something, and two cylindrical extrusions on the side that fit over the jaw hinge of the skull and are tipped with additional connection points for kanohi. Deeper in the throat, the facial cover also includes several thick, stretchy filaments whose tension and position can be controlled by small muscle strands. When air is blown over them, these strands vibrate and produce sound, becoming vocal cords.

Lastly, the frame structure is completed with the addition of digits to the hands and feet. A standard Toa’s hands have four fingers and a thumb, though the fingers can be paired by extensions to produce two larger, stronger fingers at the expense of dexterity, such as was done with Onua Mata’s hands to turn them into very effective clawed shovels. By the same token, the fingers of a Toa of Air are usually longer and naturally curved as to grasp branches and climb more easily. Matoran usually have three or two fingers, with similar tribal variations. Standard Toa and Matoran feet have two large toes that articulate individually, allowing them to clasp onto uneven terrain features to a limited degree. Again, though, there is room for modification based on need, and most Toa armor includes heavy-tipped boots that greatly limit the articulation of their toes to offer better protection. Both the fingers and toes resemble a miniature version of the core structure of the spine and are articulated by flexweave contained within their segments.

3 – Insulation, Energy Storage, and V-Bands

Though fairly resilient, the air exchangers and heart pump function best when kept within a reasonable temperature range and free of dust. To keep them working optimally, then, a the chest must be sealed. On the surface, this is done through a fine metal mesh stretched from the upper ring from the #4 vertebra to the larger ring of the #7 vertebra. The mesh is strong enough to offer some protection and is lined with a film on the inside to keep out dust, but it does little to insulate from heat: for this, bladders of battery gel called reservoirs are used. Battery gel is a gelatinous, organic substance capable of absorbing and storing tremendous amounts of heat, making it an excellent thermal regulator. It can also store a great electrical charge, allowing it to function as a battery to run the Toa’s heart pump and brain and giving the substance its name. Battery gel tends to liquefy in contact with air or metal, however, and is therefore contained in tough, flexible bladders called reservoirs (also made of organic materials) that are fitted all over the body.

The largest reservoir on the body is fitted to the base of the skull and drapes out over the shoulders to cover most of the chest area and down to a similar position on the back. It encases the ball joints of the shoulders, releasing and sealing a lubricant into them to keep them from seizing and over the bones of the arms to keep the blood inside them from boiling or freezing in extreme temperatures. The nodules still poke through it, however, to allow attachment of the muscle strands over the top of it. The second largest reservoir is fitted around the Toa’s hips, encasing the hip joints, the bones in the thighs, and the lower legs down to the ankles. Together, these two main reservoirs store a significant amount of electrical energy, organic molecules to fuel the automatic maintenance and repair of muscle strands, and keep the core structure at working temperature.

Below the surface, there are three additional reservoirs that serve a more special purpose. The first, already mentioned, is fitted around the spine and digestive tract inside the spinal assembly, serving mostly as a store for organic molecules produced by the breaking down of food in the digestive tract, a battery for the brain, supplier of lubricant to the spine, and as insulation for the digestive tract and spine. The second is fitted below the heart pump and air exchangers and completely plugs the gap between the spinal assembly and the larger ring of the #7 vertebra, sealing the chest cavity completely from the outside world in the process. Though small in surface area, it is thick in volume and serves as the primary battery for the heart pump. The third and smallest of the reservoirs is fitted inside the cylindrical extrusions of the lower facial cover; it lubricates the jaw hinge and services the otherwise difficult-to-get to muscle strands that articulate the jaw.

The elaborate shape of the reservoirs and the area that they cover may lead one to believe that they are excessively difficult to apply and vulnerable to damage. Neither of these assumptions is true due to a particular property of the material that the reservoirs themselves are made of: their ‘skin’ is self-sealing. True, a piercing of a reservoir will lead to some battery gel leaking out, but the fissure will rapidly close as chemical bonding of the skin pulls its sides closely together and fuses them. This property also makes application of the reservoirs easy; for example, the largest reservoir, that covering the upper torso, neck, and arms, is in fact a composite of seven smaller reservoirs that, having been in contact for an extended period of time, have fused together by the same mechanism that allows them to seal punctures to form one cohesive cover over the entire top of the body. Waiting for these reservoirs to fuse is the longest ‘dead time’ that is usually taken during the construction of a Matoran or Toa, as it takes about a week to naturally complete.

When all the reservoirs are in place (but not yet fused), two metal bands are fitted to the body. Often called V-bands for their shape when viewed from the front, one is fitted to the base of the neck and another around the hips. The bands are thick enough to serve as some armor for these particularly vulnerable areas, but their primary function is to serve as anchor points and guides for the muscle strands that will be stretched through underneath them. Their location is therefore significant; the upper V-band separates the neck from the torso, allowing muscle strands in that area to remain more tightly packed for both insulation and protection, and the lower V-band does the same for the legs, allowing many muscles to be tightly packed around the hips without them interfering with each other. To those familiar with the construction of a Matoran body, the shape of the V-band is a good indicator of a gender: from the front, it’s more V-shaped on female and T-shaped on male bodies. Unlike the Glatorian on which their body layout was originally based, however, neither Toa nor Matoran actually have any practical reason for wearing bands of a particular shape; these shapes are, in effect, a kind of evolutionary holdover from a previous iteration of their design.

Lastly, thin, concave metal lids are fitted on the eyes to work as eyelids and provide protection to the eyes when shut.

4 – Muscles

With all supply mechanisms for them in place, the muscle strands can be attached. Their layout roughly follows that of the human body, but with some notable differences. First, Toa and Matoran possess nowhere near the complex array of facial muscles that humans do, instead leaving the skull and the lower face cover mostly bare. The exception lies in some intricate work done around the eyes, where small muscles can produce a significant number of expressions. Secondly, no muscle strands cover the waist, since its movement is already taken care of by the spinal assembly and its flexweave. Some strands are added around the neck to more adequately support the head (kanohi, being made of metal, aren’t exactly lightweight), but the majority of strands are used primarily to animate the limbs, which are practically coated in full length. The strands covering the chest and those following a similar pattern around the back are used to adjust the shoulders and hence improve the movement range of the arms. Small muscle strains are added on the inside of the fingers and toes as well, to provide the directed strength needed for a good grip that the flexweave alone cannot provide.

As with the base frame, muscle strand layout can be varied depending on the type of Toa or Matoran that is being produced. The standard model, for example, employs ‘double-stranding,’ the fitting of two large strands from the same node on top of each other as opposed to using just one, only in the legs to allow great jumping and climbing ability, but Toa and Matoran of Earth employ it in their arms and chest area as well to provide tremendous upper body strength at the expense of greater energy consumption. In fact, any Toa or Matoran can, by adding or removing strands (up to triple layering is possible, and more with modifications to the nodes) greatly customize their strength and how they can best apply it, balancing strength in the right areas for their weapon, for example, with moderating the stress that running more strands places on their heart pump, air exchangers, and the rest of their circulatory system. For example, Toa of Water often triple-layer their legs to allow them to produce great bursts of speed underwater with fin-like appendages on their feet.

The muscle strands themselves consist of fibrous organic material stretched between two node connectors and wrapped in the same material that lines the inside of the chest cavity to keep out dust. Each muscle strand is a self-contained unit that is supplied entirely through the nodes, making replacement a relatively easy job. Injured strands do slowly heal, but as with parts of a Toa’s body, it is best to replace one if it has sustained significant damage rather than wait for it to fix itself. Unless they are completely cut in half, even severely damaged muscle strands can be hooked up to a node in a refurbishing station and allowed to heal by themselves and later be offered as a replacement to someone else; a form of body-part recycling.

It should be noted that, apart from the addition of a Kanohi mask, a Toa’s body is at this point functionally complete. In fact, without the weight and constraints on movement that armor adds, Toa are especially strong and agile and many habitually wear only their torso armor unless they expect to enter a combat scenario at some point soon. However, as their intended occupation was the defense of the Matoran, their bodies were explicitly designed with clearance for armor in mind; even when triple-layered with muscle strands, large gaps between a Toa’s thighs and between their torso and arms allow for the application of significant amounts of armor without causing the body parts to start interfering with each other’s range of movement.

5 – Armor

To a large degree for Toa and to some degree for Matoran, armor follows a set template. Armor around the chest area is worn full-time by all as it compensates for the lack of an internal ribcage, protecting the vital air exchangers and heart pump. Matoran usually wear armored boots and protection for their shins and lower arms as well, since those are areas that are both relatively vulnerable to begin with and most likely to be subjected to damage over the course of daily work or travel. Whether to wear shoulder armor is usually a personal preference thing for the Matoran (though it is popular with Onu-Matoran in particular), and only Fe-Matoran take it further by fitting plates over their thighs and upper arms. A fully-equipped Toa will usually have all these armor pieces and in greater thickness than Matoran have. Some also use small interlocking plates to cover and protect their throats.

While armor on the limbs usually consists of simple (if decorated) hinged tubes that can be locked around part of a limb, torso armor is a lot more involved to make and personalized the owner, even if the owner is a Matoran. For Toa, the weight of their armor and the whole upper body structure does mean that the spinal assembly has to work hard to hold the whole body upright, however. Because of this, torso armor worn by Toa usually incorporates at least two dampening pistons in the waist area, which help to stabilize the upper body, carry the weight of the armor, and hence reduce the stress on the spinal assembly at the expense of some flexibility in the torso. Toa with particularly heavy upper-body structures, like Toa of Earth, often use at least four of dampening pistons full-time to avoid back problems, but for most two is enough and they only use them when fully kitted up for war; when not carrying full armor and a heavy weapon around, their spinal assembly manages fine on its own.

The last thing to be added and usually the trigger for a Matoran or Toa’s activation is their kanohi. Though it is known that Matoran without kanohi will weaken and slip into a coma and Toa without kanohi will become exceedingly weak, the method by which the kanohi achieves this is not well understood. Theories abound, and most postulate that some interaction between the brain and the kanohi provides the strengthening effect by turning the kanohi into some kind of magnetic dome capable of amplifying the brain’s signals to where they are strong enough to actually control the body. Evidence for these theories lies in the fact that the material that kanohi are made of has strong magnetic properties and that the attachment points for the mask can induce a current into the kanohi. Inducing a current into the kanohi (or perhaps intensifying it) is also the way to activate the runes, usually carved on the inside, that provide the kanohi with their power.

A notable difference between kanohi produced before and after the Reformation can be found in their mouths: pre-reformation kanohi are often fitted with slats or louvres that cover the mouth completely for additional protection, while still allowing the wearer to breathe through them. These structures were usually removable to allow the wearer to eat when required, but since that was at worst a monthly occurrence and sustenance could just as easily be gotten through charging points, most used these covers full-time. However, in the aftermath of the battle between Mata Nui and Teridax, the Matoran Universe suffered a complete loss of power and hence charging points could no longer be used; Toa, Matoran, and a host of other beings had to turn food for all their nourishment, making the covers more trouble than they were worth. Maintenance issues with teeth due to the major dietary changes were eventually resolved by coating the teeth in a tough, enamel-like substance already long in use by the Skakdi, and before long eating became a less disliked activity for the Matoran Universe’s former residents. Though Spherus Magna now does have an electrical infrastructure capable of supporting a large number of charging points, Matoran society at large now has little reason to build or use them.

Full Sequence:

What do you think? Given that this is the Bionicle discussion topic, I’d particularly like to know what the discrepancies with what is known canonically about producing these beings… I don’t know much about it myself.


This is very fascinating. I think going beyond just the muscular tissue and getting into the real nitty gritty of their skeletal design and core internals really helps put into perspective just how these guys move; how they eat; how they expel waste, etc.


yo this is really awesomely detailed


Man, I really love your work… You do a great job of diving deep into the thought process; do they eat? What does their skeletal structure look like? And so on and so forth. I always look forward to the pieces you put out. :slight_smile:

Anyway, like @Stoax said, it is fascinating! Now I kinda want someone to do a MOC… Maybe I’ll have to try…


You, my friend, just wrote the book on Bionicle Anatomy…

Well done!


Absolutely brilliant!
Excellent attempt to apply biology into them while also keeping them mechanical too, at some point i was questioning the lack of pistons in the body and then you mentioned the pistons to help support weight and it made sense.
Though something that concerns me is that the arm joints are simple hinges, and well sure the sets are built like that but the human body has much more arm articulation than that.


Well, human elbows are just hinges.

We can rotate our forearms due to the structure of the ulna and radius, one sliding over and sort of around the other, like a pair of chopsticks, however I’d assume a Toa or Matoran wouldn’t need that as their wrists could simply rotate at that point.


thats not really what I mean, but looking at the shoulder joint my point is wrong anyway.


That would be very interesting to see indeed; I’m nowhere near a good enough MOCist to make that work, but I’m sure that there’s people out there that could.

There wasn’t one before? I was under the impression that somewhere in canon there was at least a half-hearted explanation of Toa and Matoran biology…

Glad that question resolved itself. :grin:


a nice idea supported by good artwork! definitely getting a like from me! :smiley:


Headcannon approved.


A little freaky, but still really cool.


I can’t help but think of Synths when i see that.

This is gr8.


Oh my god, that was… interesting.

I especially like the theory of why Matoran and Toa need to wear Kanohi.

I totally agree.


Imagine that for a Makuta :joy:

1. Gaseous essence

2. Armor



As far as canon has explained, Matoran are built by machines, are mostly mechanical, have organic muscles and organs, and require a mask to function, but nothing as in-depth as this.

You have basically become the Andreas Vesalius for the Bionicle community. :stuck_out_tongue:


Hey, that could be my custom member title…

1 Like

This is practically my thoughts on the matter. Now let’s get Greg to canonize it :stuck_out_tongue:


I think you may have overdone it on the muscle mass, considering what Greg has said about the proportions of organic and metallic mass that compose matoran anatomy, which if I remember correctly is around 20-80 respectably, even including the armor you’re illustrations feel too organic imo.

That said, I believe you’ve nailed the torso and head anatomy, though I think the limbs, given the physical molds we’ve seen across g1 are built more like exoskeletons with a combination of muscles and pistons providing motor functions to the limbs.


True, this design is probably around a 2/3rd mechanical, 1/3 organic mix by mass and definitely could feature more pistons to replace some of the muscle strands. Personally, I’d use them in the lower legs, upper arms, and movement of the shoulders, all areas where the rigid bulk of the pistons wouldn’t be too much of a problem if they were attached properly. The design presented above could then be closer to how a Toa or Matoran would be constructed post-reformation, based in part on the mostly organic bodies of Glatorian and Agori, while the more piston-ed versions would be the pre-reformation ones… It could even be an upgrade of sorts to bring the physiques of the highly customizable Toa and Matoran more in line with those of their new neighbors and make them less reliant on frequent piston lubrication.

Alternatively, the exoskeleton idea could be applied very nicely in the armor by fitting it with the pistons that the base design lacks, kind of like how it does use pistons in the waist area. This would turn parts of the armor into a kind of power-assisted suit, and adding that power to it means that the armor could be heavier and offer more protection without impeding movement as much.

The brainstorming continues…