Grung was once a Toa of Air who completed his destiny and became a Turaga. He never watched over a village and just decided to live on a island in the Southern Continent. Bevio once met him, and they became friends.He later migrated the robot when Teridax died. He told Bevio to believe in himself and protect the Matoran and Agori from the Doom Event. Grung attended at Clawkiller's funeral.
As a Toa, he had a green Kanohi Arthron, Mask of Sonar. He had this as a Turaga too, until he escaped the robot and lost it. He has a Jungle Tribe helmet he found as a mask now. As a Toa, he had a Air Scythe. As a Turaga, he has a staff.