Lord Chapu-Chapu, also referred to as the King of the Swamp, is the ruler of the waters of the swamp of Woodfall. He can be encountered and caught at the Swamp Fishing Hole.
Little is known about him, other than the fact that he only appears when all other fish have been caught, but Link must then exit and reenter the fishing hole until he finds Lord Chapu-Chapu.
He appears to have an affinity for small fish, as it is the only thing that will lure him in to be able to be caught.
His Ocean Fishing Hole counterpart is the Great Fairy Fish.