Kopaka is the Toa of Doors. He is the nerd of the Toa Nuva team. He likes to eat cheese. He wields a Cheese-blaster that shoots molten cheese at an enemy and cools/solidifies upon stiking them! He is currently trying to block the mice who keep chasing him behind several layers of doors.
Kopaka wore a Great Kanohi Gopok, Mask of Cheese-Vision. Kopaka used his Gopok to see through the molten cheese, launched from his blaster, that covered a screaming Matoran so he could she what his skeleton looked like.