- "Jumpin' jellyfish! I don't believe it! That there fishy is one they call the king o' the swamp! Good work, pal! Congrats and all that!"
- — Swamp Fishing Hole Owner
Lord Chapu-Chapu is a species of Fish that can be caught in the Swamp Fishing Hole in the 3DS remake of The Legend of Zelda: Majora's Mask. Unlike other fish in the Swamp Fishing Hole, Lord Chapu-Chapu is not listed on any of the posters on the wall across from the propitiator and as a result acts a secret Boss Fish. Lord Chapu-Chapu resembles a smaller version of Lord Jabu-Jabu from Ocarina of Time. Although smaller than Jabu-Jabu, Chapu-Chapu still is large enough to outclass Young Link by a significant amount, with Young Link barely making up a fifth of Chapu-Chapu's overall size. Upon being caught, the propitiator revealed that it is the legendary King o' the Swamp and congratulates Link for catching it. However befitting its legendary status, Lord Chapu-Chapu is by far the hardest fish to land in the Swamp, requiring time, patience, and a lot of effort to land successfully.
Given its resemblance to Lord Jabu-Jabu, Lord Chapu-Chapu may be his Terminan counterpart. While Lord Chapu-Chapu is not consider a Deity in Termina, he is considered a Legendary Fish and it should be noted that counterparts do not always share roles (for example Ruto's counterpart Lulu is a famous Zora Singer and not a Zora Princess or a Sage). Also while Lord Chapu-Chapu is not as massive as Lord Jabu-Jabu (who is as big as a whale), it is the largest fish in the Swamp Fishing Hole and Lord Jabu-Jabu's size could be due to his divine status.
Majora's Mask Beta elements
Its presence in Majora's Mask 3D, may have been inspired by early production concepts from the development of the original Majora's Mask for the Nintendo 64 that never made it into the final product, as Shigeru Miyamoto told Famitsu that there was going to be an enhanced fishing mini-game (which may have inspired the Fishing Holes that appear in Majora's Mask 3D). In one of the early concepts for the origin game, Link would be fishing for the legendary Jabu-Jabu and if he managed to catch the giant fish it would have effects such as halting the fall of the Moon. It is possible that this later inspired the developers of the 3DS remake to create Lord Chapu-Chapu (basically a scaled down version of Jabu-Jabu, though catching Lord Chapu-Chapu does not have any effect on the game's story).