Krahka

A Krahka was an intelligent shapeshifting Rahi. One for years made her home in the tunnels beneath the Archives. She had the unique ability to change her form into that of any living being she had seen. In the proccess she gained the powers of those she imitated, could mimic their voices perfectly, and even gained some of their knowledge. A Krahka was capable of speaking and understanding Matoran, forming complex strategies, and decieving virtually anyone. Only the Rahaga had been able to pierce their disguises.

History
The Toa Metru first encountered this Rahi while investigating a possible flood in the Archives. The Krahka almost succeeded in defeating them, only to fall when she tried to duplicate the powers of all six Toa at once.

Battle for Metru Nui and Voya Nui Saga
After being defeated again by Roodaka, she temporarily joined the Visorak Viceroy, planning all along to betray her. She later began to aid the Toa Hordika. She vanished into the Zone of Darkness along with Tahtorak and a Zivon. The Krahka and Tahtorak returned through a dimensional gate created by Brutaka while he tried to defeat Axonn.

Reign of Shadows
After the awakening of Mata Nui, the Turaga located Krahka on Metru Nui, where she agreed to aid them in their fight against Teridax. She found herself in Karzahni as part of a team with Tahu, Kopeke, "Guardian", Johmak, and Lariska. She witnessed Guardian leaving the team and promptly getting killed, and the team was then discovered by Exo-Toa. It is unknown what happened to Krahka in the ensuing confrontation.

Personality
A Krahka had a very distinct personality, considering they are Rahi. They were very defensive of their territory, and will protect it at any cost.