Kralhi

Kralhi were the first attempt to create law enforcement robots for Metru Nui.

History
Kralhi were created by Nuparu after a sudden need for law enforcement on Metru Nui. However, they soon proved to be an inefficient method of stopping Matoran lawbreakers, as the goal was to render them unable to cause trouble and get them back to work as soon as possible. Victims of the Kralhi would need be unable to work for days as a result of the energy loss due to the bubbles their tails fired. Therefore, the Kralhi were deemed a failure and discontinued. The Matoran attempted to scrap them, however, they resisted and escaped. With the help of the newly-created Vahki, the Matoran were able to drive a group of Kralhi out of the city, eventually taking up residence in one of the large waterways leading to the island above.

Much later, when the Onu-Matoran Archivist Mavrah left the city with a group of ancient, enormous Rahi, he encountered the Kralhi. At first, he was afraid they would attack him; instead, they still seemed to be driven by the programming of their original mission: to serve and protect the Matoran. For years, Mavrah, the Kralhi, and the Rahi lived in peace, until the Toa Metru came through the waterway bringing six Matoran to safety. Mavrah, who knew nothing of Teridax's attempted takeover of Metru Nui, assumed the Toa had been sent by Turaga Dume to bring him back, and ordered the Kralhi to capture them. A lengthy three-way battle ensued between the Toa, the Kralhi, and the Rahi, which was further complicated by the arrival of several dozen Vahki. In the end, the Kralhi were destroyed, Mavrah was presumed dead after being washed away by a massive wave, the Rahi driven into the lake, and the Toa Metru trapped the remaining Vahki under a landslide.

Abilities and Traits
Kralhi were scorpion-like machines whose tails could produce and fire energy spheres to imprison a target. The sphere then drained the victim's energy until they passed out, directing that energy back to the Kralhi.

Trivia

 * Kralhi could be built as a combiner set consisting of Toa Metru Onewa, Vakama, and Matau.

Kralhi