Matoran

Matoran are the "average" people of the Bionicle world. The Matoran have a work based culture and uphold many virtues, primarily Unity, Duty and Destiny. Although not one of Bionicle's strongest races, Matoran are the most common and possibly the most influential, seeing as most all intelligent beings speak the Matoran language. The Matoran are also the chosen people of the universe's protector, the Great Spirit Mata Nui.

All Matoran wear Kanohi Masks that keep them functioning and healthy; a Matoran who loses his mask will quickly go into a coma-like state until a mask is replaced on his face. They do not have the mental strength to activate the powers that Great- and Noble-level Kanohi hold, but if they wear such masks they can sense that power is present. Matoran also have a little bit of power of a natural element; just enough to influence their physical abilities.

Certain destined Matoran have special power hidden within them; when this power is unleashed the Matoran transforms into a heroic Toa warrior with increased physical strength and elemental power.

Mata Nui/Metru Nui Matoran
Though the Matoran from Metru Nui have physically transformed a few times over their lives, some things have remained constant. First, each Matoran has up to three colors on their bodies: one for their torso, one for their feet and sometimes their hands, and one for their mask; oftentimes their mask color matches their limbs. Second, they invariably wear one of twelve Kanohi Mask shapes: Great Akaku, Great Hau, Great Kakama, Great Kaukau, Great Miru, Great Pakari, Noble Huna, Noble Komau, Noble Mahiki, Noble Matatu, Noble Rau, and Noble Ruru.

When Matoran first come into being (on Metru Nui, at least), their bodies are characterized by their large, flat, triangular torsos. Their masks also have silver streaks on the forehead that show the masks are powerless. Matoran of this body style are known among some fans as "Metruan".

When Makuta put the Matoran into Matoran Spheres, the spheres eventually caused the Matoran to weaken and physically shrink. In this weakened state, the Matoran had very small torsos, large two-toed feet, and gangly oversized arms. This form of Matoran is called "Mctoran" by some fans, as their toy sets were distributed as prizes in McDonald's Happy Meals.

After the Bohrok-Kal were defeated, the Turaga revealed to the Matoran how they could rebuild their bodies into stronger forms that would be roughly comparable to the bodies they once had on Metru Nui. These forms were not as tall as their Metru Nui forms, but were quite a bit bulkier; and they kept the two-toed feet of their previous incarnation.

Voya Nui Matoran
A thousand years ago during the Great Cataclysm, the region around Mount Valmai "rocketed up" off of a continent and became an isolated island, Voya Nui, stranding the Matoran and other beings living there. Since then the Matoran have had to struggle to survive, dealing with constant drought and volcanic eruptions. At some point, a settlement sank beneath the sea, and the Matoran still throw food and gifts into the sea in memory of those lost that day. Unlike other known islands, where Matoran are separated by type, all of Voya Nui's survivors have banded together and live in a single fortress.

It has been implied that at some point before the Cataclysm, the Matoran were sent to Karzahni for repairs. However, Karzahni's workmanship wasn't the best, and he gave them weapons for defense to make up for it. He then sent them to Mount Valmai rather than where they originally came from, rather than admit to his bad handiwork.

The Matoran of Voya Nui have never seen a Toa, and their leader, Turaga Jovan, died in the Cataclysm. Since they have no protectors, some of them have become great warriors. But since they have never seen a Toa, they accepted the claims of six beings who said they were Toa come to save them. Unfortunately, they were not Toa but Piraka - "thieves and murderers" who soon dropped their act and enslaved most of the Matoran.

A few Matoran were able to escape enslavement, and have begun to fight back. They allied themselves with the Toa Nuva once they accepted that they really were Toa and not pretenders; and after the Nuva were captured they met and teamed up with the Toa Inika. Working together, they were able to free some of their enslaved friends; and now while the Inika and Piraka are searching for the Ignika Mask of Life, the Matoran rebels have the mission of finding and freeing the Toa Nuva. But in their search, they found some shocking information - that those lost in the sunken settlement may still be alive!

Due to Karzahni's shoddy repair jobs, the Matoran on Voya Nui are physically weaker than most Matoran, and there is no uniform body style. There is also no uniform set of masks that the Matoran wear, as Karzahni just gave them whatever masks he had lying around.

Types
Matoran are classified whichever element they are affiliated with. So far, only Matoran of Bionicle's major six elements are identified, though there are surely more in existence; we know this because Matoran do not change elemental type upon becoming Toa, yet there are Toa of other elements besides the main six.