The Master of the Swamp (沼の主 Numa no Nushi), also known as the Lord of the Lake, is a whale-sized fish living in the swamp of Whale Island. Despite its difficulty of capture, five fishermen being unable to reel him in at once, Gon Freecss caught the fish at the age of eleven. In the 2011 anime adaptation, Ging is said to have achieved the same feat when he was twelve.
- In the Nippon Animation adaptation, Gon releases the fish after Mito signs his Hunter Exam application card. However, its fate is unknown in the manga.