The One Fish Rarities: Mythical, Shiny, Sizes & Values
How rarities work in The One Fish: the Mythical tier above Legendary from UPDATE 1, shiny fish, and fish sizes that change the quota value of each catch.
The One Fish’s rarity system has grown past the launch build: UPDATE 1 (August 22) added a Mythical tier above Legendary, fish sizes that affect quota value, and the Fishopedia showcase. The launch-era ladder (ordinary → rare → shiny) still exists, but a new top tier now sits above it. Everything below is tagged to its source: official store text where re:try said it, official patch notes where the developer announced it, player footage where streams showed it, and not yet confirmed wherever no source exists.
Version note: rarities, values and rarity mechanics on this page were checked on August 29, 2026 against UPDATE 1 (Aug 22) and Update 1.1 (Aug 29); player-measured numbers can change with any patch.
Mythical: The New Top Tier
The official UPDATE 1 announcement states it plainly: “We added 5 new fish and 6 new hats to the game, as well as a new Mythical tier for fish that are higher than Legendary.” Before this patch, the game’s ladder had no single official rarity tier list published; launch-week streams showed ordinary, rare and shiny tiers. Now the developer has named a top tier: Mythical > Legendary. Any fish at or above Legendary in the current build is chasing that Mythical tier.
The announcement does not name a Mythical fish or publish its drop rate. This page does not invent one — the honest statement is: re:try confirmed the tier exists and is higher than Legendary.
Fish Sizes: A New Value Dial
UPDATE 1 added sizes, and size matters: “Fish can now be caught at different sizes! Fish sizes affect their quota value too. Try to find the biggest Small-Small Fish you can.” This means the launch-era “one fish = one value” model is gone. A Small-Small Fish is not automatically junk — the biggest one competes with bigger fish on quota. When you are comparing catches, compare record size, not just species.
The Fishopedia supports this: “click any of the fish you’ve discovered. It will showcase your record size and shiny variant if you have it.”
Shiny Fish
Shiny fish exist and are extremely rare — launch-week footage shows a shiny pull being called out as the highlight of a session, and at least one confirmed shiny catch carried a Luffy-style straw hat. UPDATE 1 does not change the shiny status; shiny variants now get showcased in the Fishopedia alongside the record size. No official shiny rate is published.
The Rarity Upgrade (Launch-era, still with the caveats)
The launch build had a shop rarity upgrade raising the chance of rarer fish, and a Chance/Luck gamble beside it. UPDATE 1’s balance pass did not remove these, but it did remove the shop stat upgrades (Health, Hunger, Luck, Strength) in favor of the level system, adjusted fish rarities and stat upgrades, and changed super bait chances (Update 1.1: “adjusted super bait chances to be more balanced”). Exact odds remain unpublished.
Fish Values
Launch-week players measured real per-fish values from 15 up to 1500+. UPDATE 1’s size system changes what those numbers mean: the same species is now worth different quota depending on size. The 1500+ figure from the launch build likely describes a large or rare catch of a big species; without official per-species value tables, the safe statement remains “value varies by species, rarity and now size.”
Biome Exclusivity Changed How You Chase Rares (UPDATE 2)
Before September 26, 2026, rarity and species were mostly separate questions: you could chase a rarity anywhere, and a species could turn up in more than one place. UPDATE 2 changed that. The official announcement states that fish species are now exclusive to their biome, both in the two new biomes and in the existing ones.
Two consequences follow directly from that wording:
- A rare you want may now only exist in one biome. Because the new biomes also carry “a higher chance of rare fish,” the highest-value catches are concentrated in the newest, hardest tiers — so rarity farming is now a question of where you fish, not just how you upgrade.
- Biome access is gated by ship hardware. Reaching the new tiers requires fitting the Rocket and Submarine parts, so before you can chase anything in the new biomes you need those upgrades first.
The developer frames the change as making the Fishopedia “more of a journey,” and says new species should keep appearing in each biome as development continues — which means the exclusivity map is a moving target rather than a fixed table.
What Is Still Unknown
- Which species live in which biome. Exclusivity is now official policy; the per-biome species list is not published, and the two new biomes are unnamed.
- The complete official rarity table. Only “Mythical tier above Legendary” is confirmed by name; ordinary/rare/shiny remain player-observed shorthand.
- Official odds. Shiny rate, Mythical rate, and the rarity upgrade’s exact effect are not published.
- A value table. Per-fish and per-size prices have not been published.
- Whether junk pulls (boots, shoes, hats) count toward quota or score.
- Whether the Chance/Luck gamble still stacks with the rarity upgrade after the economy rework.