Turahk was one of the villains in the BIONICLE series and the secondary antagonist of the 2003 storyline. He was also the leader of the six Rahkshi released by Makuta Teridax in an attempt to prevent the approach of the seventh Toa. Turahk is known as the Rahkshi of Fear and he have the ability to spread fear and panic towards his opponents through the power from his Staff of Fear.
Following the defeat of the three Rahkshi: Guurahk, Lerahk and Panrahk at the hand of Kopaka in Ko-Koro in the island of Mata Nui, Teridax decides to use the Kraata to create three new Rahkshi; Turahk, Kurahk and Vorahk as he believed that their powers will eventually destroy the Toa's destiny. He then send them to find the two Matoran; Jaller and Takua to prevent them from searching for the Toa of Light.Later, Turahk, Kurahk and Vorahk invaded Onu-Koro and start attacking the Matoran and headed towards Takua. The two Toa, Pohatu and Onua tried to take down the Rahkshi, only to be bested by them during the fight. While Onua have his power drained by Vorahk, Pohatu attempt to help his friend, only to be intercepted by Turahk, who hit him with his Fear energy, causing Pohatu to succumb with fear. All hope are losing until the arrival of the other Toa Nuva who arrive in the scene, though Tahu was hit by Kurahk, thus causing the former to turn on his allies. Tahu was on the blind rampage until Kopaka freeze him. During the chaos, Turahk tried to catch Takua but could as he and the other two were trapped by Onua as Onu-Koro started to collapse but the heroes, Takua and the Onu-Matoran manage to escape.
However, Turahk and the two Rahkshi manages to survive the collision and along with Guurahk, Lerahk and Panrahk, the six Rahkshi continue their search for Jaller and Takua. They eventually tracked them down in Kini-Nui as they cornered the two Matoran just when the Toa Nuva arrived. The Toa Nuva then engaged the Rahkshi into battle. They fought with each other; however this time, the Toa were gaining the upper hand on besting the Rahkshi. The Rahkshi then transformed into their Kaita form: Rahkshi Kaita Vo and Rahkshi Kaita Za. Despite their formidable powers, the Rahkshi Kaita were even bested by the Toa as Turahk split off from both Lerahk and Kurahk as he was accidentantly knocked out by Rahkshi Kaita Vo and fall unconcious.After the Toa successfully defeated the other five Rahkshi, Turahk suddenly regained consiousness and began chasing after Jaller and Takua before being attacked by Pewku, an Ussal Crab. But he threw her aside and trapped Takua in a wall of terror, as the Matoran attempt to run. Turahk then uses his Staff of Fear to finish off Takua, only to be intercepted by Jaller who sacrificed himself by getting himself killed by the energy blast. Turahk then attacked by Gali and Pohatu before he knocked them aside. He then prepare to kill Takua but Jaller's sacrifice caused Takua into donning the Kanohi Avohkii and transform into Takunuva, the Toa of Light. Takanuva then engaged Turahk into the last fight. Though Turahk barely put up a fight, he was eventually overwhelmed by Takanuva's power and incinerated by him with Light energy.
Later, Turahk's and the other Rahkshi's remains were eventually dismantled and used to make an Ussanui.
- Teridax chose to sent Turahk to stop the arrival of Takanuva beacuse Fear was in direct opposition to the Ta-Matoran Principle of Courage based on his color scheme.