Roll a Fisherman Mutations Guide: All 6 Types, Costs, and Odds

What mutations do

A mutation multiplies a fish’s earnings. The community’s recorded wins show the ceiling: a Galaxy sawfish earning 31k/s, a Glitched anglerfish climbing from ~140k/s to ~840k/s after later bonuses. There is no published multiplier table — the game reveals each result by what the fish earns afterward — but the direction is always the same: mutated fish out-earn their plain versions.

The six mutation types

All six confirmed types, with what players have observed:

How the mutation machine works

The machine stands next to the Gold upgrades stand, and the rules are short:

1. Hold a fish first. Approach empty-handed and the machine tells you: “Hold a fish first.”
2. Pay per roll. 100 Gold per attempt; Coral Zoey halves it to 50 — her passive is the only known discount. One player only discovered the discount mid-roll (“It’s 50 cuz it’s half price. Just didn’t tell me.”), so check your balance before and after.
3. Or mutate on catch. Landing a fish can pop a “Do I mutate this?” prompt on the spot — same machine, same price, zero walking.
4. Read the new odds screen. The displayed chances change between attempts — Glitched has been seen at 1%, 8%, 3.5%, and 1.5% on the same target across one session. The screen is the only odds source that matters at that moment.

What to mutate: the value rule

The entire strategy is one sentence: mutate high-base-value fish only. A 100-Gold roll on a shrimp and on a mythic Beluga cost the same, so the Beluga is the correct target every time — the community’s recorded wins were all high-base-value fish. The classic target is the mythic Beluga (6.35k base value); one player mutated theirs on sight (“6.35k base value. Yeah, we’re mutating you, bud.”).

• Keep a 100 Gold reserve banked at all times so a mythic catch can be mutated immediately — the Gold guide covers the banking habit.
• If you plan a heavy mutation session, Coral Zoey’s halved rolls can pay for her price across the run — her stats are in the fishermen list.
• The Mutation Luck upgrade improves machine odds but only matters once you are mutating regularly; the purchase order is in the upgrades guide.

Collectible notes

• Born-mutated fish exist. Read every result card before bulk-selling — a shiny or galaxy catch is worth far more than its plain cousin.
• The Prismatic title requires catching a fish of every mutation — a long-term collection goal that doubles as a tour of the machine.
• Mutation values moved before (the 2026-09-22 rebalance touched the economy), so re-check after-earnings on your old mutations after major patches.