Kraahkan

The Kanohi Kraahkan was the Great Mask of Shadows. It was made and kept in Artahka, until it was stolen by the Makuta.

When Makuta Teridax and Toa Takanuva merged to form Takutanuva, the Kraahkan and Avohkii also merged, forming a mask with the powers of both Light and Shadow, or unofficially known as the Mask of Light and Darkness. However, the two beings and their masks soon split apart again.

When the Piraka entered Mangaia, Reidak attempted to claim the Kraakhan from the shattered armor of Teridax, but it pummeled him with energy until he threw it into the Silver Sea.

Sometime after this, Makuta Icarax dived into the sea and emerged with the Kanohi Kraahkan. He then replaced his mask with the Kraahkan. However, the Kraahkan, along with Icarax, was dispersed into atoms throughout the universe when Gorast and Vamprah killed Icarax, who had been trying to use his powers over teleportation, in Karda Nui.

Teridax later formed the stars above Metru Nui into the shape of the Kanohi Kraahkan when he announced the success of The Plan to the whole Matoran Universe.

The Kingdom
In The Kingdom Alternate Universe, the main dimension's Takanuva knocked the Kanohi Kraahkan off that timeline's Teridax during the Battle at the Light Barrier. Toa Tanma then destroyed the mask.

Dark Mirror
In the Toa Empire Alternate Universe, the Kanohi Kraahkan was taken from Teridax by the Toa Empire and put in the Archives as a trophy. It was wired, so that if anyone touched it, the Toa Empire would know.

The Melding
In this Alternate Universe where Makuta were good, Teridax wore a gold Mask of Shadows, but its power was not associated with evil.

Powers
It allowed the user to control the shadows and feed fear and/or anger into those affected by its power. It could also let the user see the evil in others. It can also strike non-Makuta who attempt to take the mask with blasts of Shadow.

Wearers

 * Teridax (Formerly)
 * Icarax (Formerly)
 * Alternate Teridax

Trivia

 * A Toa would not wear the Kraahkan, as they considered its power immoral.
 * In the Parallel Universe, the Kraahkan was displayed unguarded in the Metru Nui Archives as a trophy, and as an insult to Teridax.
 * In The Kingdom Universe, the Kraahkan was retrieved by Teridax after he killed Icarax, but it was destroyed by Toa Tanma.
 * A gold version of the mask was released in a playset--Tower of Toa
 * The Kraahkan was one of the first two masks to have a cross axle part to connect it to the bearer.
 * The Kraahkan was the first flip mask, of which only two exists (the other being the Vezon version of the Ignika). Among the two, only the Kraahkan is a true mask in both forms, as Ignika's second form served as Vezon's face. But in every set that has the Kraahkan, it always shown the second form.
 * There are a total of 4 different shapes of the Kraahkan; the original one that came with "The Makuta" set, a "movie" version that came with the limited edition Takutanuva set (who's second face resembled the Kraahkan depicted in the movie rather than the Avohkii the original resembled), a second movie version (this time designed to fit over the head of the "Ultimate Dume" model), and a re-released version of the original Kraahkan, having 2 of the 6 slits on the cheeks of the mask filled in. The final version of the Kraahkan was released in both Gold and Black, in the Tower of Toa and Icarax sets respectively.
 * The set version and the movie version has completely different shape and color.