Mutations raise the sale value and earning rate of newly discovered fish in +1 Drain Water Per Click. The set is Gold, Diamond, Venom, and Hole.
The mutation values are an August 20, 2026 snapshot. Check the live fish label and weather UI after updates.
These are the four fish mutations and their multipliers
Use the name above the fish as your main check. Color helps too, although Roblox lighting sometimes gives every fish a suspicious purple makeover.
| Mutation | multiplier | look and label | way to find it |
|---|---|---|---|
| Gold | 2x | Gold-like look with a Gold label | Higher natural chance |
| Diamond | 5x | Cyan look with a Diamond label | Higher natural chance |
| Venom | 10x | Neon-green look with a Venom label | Low natural chance; Poison weather helps new spawns |
| Hole | 20x | Dark look with a Hole label | Low natural chance; Black Hole weather helps new spawns |
These are snapshot values, not a permanent odds chart. Exact natural spawn percentages and area-by-area rates are not confirmed.
Pick up mutated fish before they despawn
Mutated fish can appear across the map. Use the normal Water and pool loop, then give every new fish a quick label check.
- Click for Water. Build up Water through the regular click loop.
- Drain a pool. Draining pools reveals fish and keeps the discovery loop moving.
- Check the label above each fish. Look for Gold, Diamond, Venom, or Hole before moving on.
- Pick up a mutation quickly. A mutated fish must be collected before it despawns.
- Scan each new area. Do not stop after checking one pool.
Weather does not reroll fish already in your aquarium or inventory. Its effect applies to the chance of new mutated-fish spawns, so watch new fish instead of waiting for an old catch to change clothes.
Use Poison and Black Hole weather for rare mutations
The pairing is Poison weather for Venom fish and Black Hole weather for Hole fish. Both weather events use a +10% spawn-chance boost and a four-minute duration for both weather events.
These weather numbers are snapshot values from August 20, 2026. They are not a confirmed permanent schedule, and no exact event timing should be assumed. When either event appears, focus on fish that spawn during the active window.
Gold and Diamond are as the more likely natural-spawn mutations, so you can find them without waiting for weather. Venom and Hole are to have low natural chances, which makes their matching weather windows the practical time to watch closely.
A fish can have only one mutation at a time. Mutation rules from other Roblox games do not carry over: Build a Base and Steal Pet Mutations covers a separate pet system, while Greedy Growers mutations and multipliers covers a separate fruit-value system.
If the live game panel disagrees with any release-meta number here, follow the in-game label and event UI.
