Kanohi

Kanohi were power-imbued masks worn by bio-mechanical beings. Kanohi masks came in many shapes and elements, and had varying powers and levels of power. They were forged using molten Protodermis, or the remains of Kanoka. Many beings, including the Matoran, would die or go into a coma if their masks were kept off for too long.

Toa Mata(2001)

 * Hau(used by Tahu)
 * Kaukau(used by Gali)
 * Miru(used by Lewa)
 * Kakama(used by Pohatu)
 * Akaku(used by Kopaka)
 * Pakari(used by Onua)

Toa Metru/Toa Hordika(2004-5)

 * Huna(used by Vakama)
 * Rau (used by Nokama)
 * Mahiki(used by Matau)
 * Komau(used by Onewa)
 * Ruru(used by Whenua)
 * Matatu(used by Nuju)

Toa Inika(2006)

 * Calix(used by Jaller)
 * Elda(used by Hahli)
 * Suletu(used by Kongu)
 * Sanok(used by Hewkii)
 * Kadin(used by Nuparu)
 * Iden(used by Matoro)

Toa Mahri(2007)

 * Tryna(used by Matoro)
 * Arthron(used by Jaller)
 * Volitak(used by Nuparu)
 * Faxon(used by Hahli)
 * Zatth(used by Kongu)
 * Garai(used by Hewkii)

Others(2001-?)
These are different types of masks (Kanohi) worn by other and titans & warriors. So, if you want to know who wears them, feel free to click on the names!
 * Avohkii
 * Rode
 * Olmak
 * Kualsi
 * Pehkui
 * Kiril
 * Olisi
 * Mask of Creation
 * Rua
 * Aki
 * Mask of Intangibility
 * Kanohi of Elemental Energy
 * Mask of Possibilities

Great Kanohi
Great Kanohi were worn by Toa and many other powerful beings, such as Makuta, Karzahni, and members of the Order of Mata Nui. They could be forged from level 8 or higher Kanoka disks.

Noble Kanohi
Noble Kanohi were less powerful versions of Great Kanohi. In addition to Toa, Turaga also wear these masks. They were forged from level 7 Kanoka disks. They are also created when a Toa becomes a Turaga from their old mask.

Powerless Kanohi
Powerless Kanohi were basic Kanohi with no special powers. Matoran had to wear them or else they would slowly get weaker, and eventually go into a coma-like state. Umbra wore a powerless mask in the shape of a Great Ruru. They were forged from level 6 or lower Kanoka disks.

Golden Kanohi
When the Toa Mata collected 6 Great Masks each, they exchanged them for a Golden Kanohi. After they defeated the Bahrag, the Toa Mata lost their Golden Kanohi in exchange for Kanohi Nuva

These special Kanohi had the powers of the Hau, Akaku, Miru, Pakari, Kakama, and Kaukau.

Other golden Kanohi do exist, but they are Kanohi belonging to other classes, just colored gold, such as Lhikan's, Brutaka's, or Iruini's.

Silver Kanohi
The same way six different Great Kanohi can be trade for one Golden, three can be trade for one Silver. It is probable that two Silver Kanohi with no common power could be trade for one golden Kanohi. The Rua looked like a Silver Kanohi.

Protodermis Kanohi
Protodermis Kanohi are masks that are not being worn or are drained of their power. They have also been described as being dull gray.

Copper Masks of Victory
These powerless copper Kanohi were awarded to Matoran as trophies for winning sports tournaments. Takua, Onepu, and Hewkii were known to possess them.

Infected Kanohi
Infected Kanohi were Kanohi that have been infected by kraata. They were rusted and old-looking in appearance, and the wearer was controlled by Makuta.

Kanohi Nuva
Kanohi Nuva were the Kanohi that had been collected by the Toa Nuva. They possess greater powers than ordinary Great Kanohi masks and can grant their wearer to share its powers with others nearby.

Hordika Kanohi
When the Toa Metru became Toa Hordika their Kanohi became stuck to their faces and lost their powers. However, Toa Nuju was still able to use the eyepiece he had built in to his original mask.

Organic Kanohi
When the Toa Inika came to Voya Nui, their Kanohi were changed by the lightning. They became organic and sentient, so as to help the Toa Inika learn their powers more quickly.

Legendary Kanohi
These Kanohi were very powerful, and sought by many beings. The Kanohi Ignika and the Kanohi Vahi were considered Legendary.

Elemental Kanohi
An elemental Kanohi was a Kanohi that allowed the user to use an element. They were usually created from the Toa disk of a Toa that element, but the four most well-known elemental masks, the Vahi, Ignika, Avohkii, and Kraahkan were made in other ways. The only other elemental Kanohi seen in the story was Toa Mahri Hewkii's Garai.