I'd like to make the request to add secret legendary fish that have an ultra low spawn rate and are not described anywhere in the game. Rare should include these fish without letting people know and have no way for players to know they've been added.
These fish would have very difficult fishing minigame mechanics and require the player to have earned an upgraded rod.
These fish also would not be capable of being eaten nor cooked and would act as perishable goods that the player would have to deliver to the hunter's call similar to how flowers wilt over time when not watered. They'd have to be stored on the ship and would flop around. If the ship had water in the lower hull the fish would swim around and would not die from suffocating, but would require the player to chase it down to pick it back up. The fish would have 3 categories of quality. Rotten, Dead, Alive. Alive would award the player a MASSIVE chunk of xp and gold. Dead would grant a slightly smaller sized amount. Rotten would barely grant any at all. The fish would immediately fill your hands upon reeling it in all the way and it would cause the player to struggle with the fish while walking making the player walk slower until the fish died. Once dead the fish would just be cargo. Dead fish will rot regardless of if it's submerged or not. Live fish will never rot, but may starve if the player takes too long to deliver the fish. The time a fish can be out of water is relative to the time a player can be underwater.