Gadunka is a major antagonist in the Lego BIONICLE series. It was once a small Rahi before it was unwittingly exposed itself to the Kanohi Ignika's energy, thus transforming into a large, vicious monster.
History
When Nocturn placed the Kanohi Ignika onto the seaweeds, a lone Gadunka scurried under the mask for shelter, unknowingly exposing itself to the mask's energy. The energy then transformerd Gadunka into the form of the monstrous creature.
Gallery
The enlarged Gadunka attacking Toa Nuparu and Hewkii