The Toa Metru looked down and did his best to ignore the advancing creature.  He willed the earth to rise, to form an impenetrable wall between him and the Rahkshi.  He could see the soil beginning to shift, running together and then swirling as if mini cyclones had taken hold.

It was a toss-up who was more shocked by what happened next, the Rahkshi or Whenua.  A mound of earth suddenly rose from the floor, hardening rapidly and blocking the creature from coming closer.

~Greg Farshtey, Mystery of Metru Nui, pg 62