Manas

Most species of Rahi are not very smart. They use their strenght- not their wits- to battle their opponents. But the most dangerous Rahi, the Manas, were both smart and strong. These gigantic, crab-like creatures were often used as guards, Makuta controlled two Manas that were later freed (these same two were later encountered by Toa Onua and Turaga Whenua), and Karzahni had several Manas in his realm. These Rahi were also attracted to heat. No single Toa could hope to overcome the Manas. The only way the Toa Mata could defeat them was by merging into the Toa Kaita.

Trivia

 * Manas is the Matoran word for monster.
 * In the wild, Manas tended to turn on each other when they ran out of opponents to fight.

Set Information
The Manas were the only BIONICLE sets that could be controlled by remote control.