+1 Drain Water Per Click Fish Mutations Tier List

Mutations are the multiplier stamped on a fish after a pool drains in +1 Drain Water Per Click. They raise Cash on sell and income per minute if you display the fish in an aquarium. This list is current-meta opinion for August–September 2026, not an official Wrestling Elephant Studio table. The Roblox game is free to play on six-player servers and has been live since 25 July 2026.

Four mutations are confirmed. We rank them S through C by multiplier, then by how hard they are to see in the wild. Weather does not create a fifth mutation; it only tilts the rare ones for a short window.

The S–C ranks

• S — Hole (20×). Dark look. Low natural rate. Best mutation in the game. A Hole fish is a Cash event, not a flex screenshot you sit on forever unless the aquarium income beats the next pump.
• A — Venom (10×). Neon green. Low natural rate. Half of Hole, still huge. Keep it unless you are one pump short and the sell price closes that gap immediately.
• B — Diamond (5×). Cyan. Naturally common. Good. Not rare enough to rearrange your whole session.
• C — Gold (2×). Gold look. Naturally common. A shiny consolation. Sell it when you need backpack space.

Hole is best. That sentence is the list.

Weather hunting

Two weather types matter, each for about four minutes at roughly +10%:

• Poison weather tilts Venom.
• Black Hole weather tilts Hole.

Ten percent on a low natural rate is still the difference between a dry drain and a 20× bag. When Black Hole is up, stop sightseeing. Drain, bag, repeat until the timer dies. Poison gets the same respect for Venom. Gold and Diamond do not get a weather button; they already show up on ordinary drains.

You will miss windows if you are across the map selling commons. That is a backpack problem, not a luck problem. Buy a +1 backpack level when you pass the stand, dump junk fish, and be next to a pool before the sky changes. The fish collection guide covers those trips in order.

Sell versus aquarium, with mutation math

Every fish is a fork: sell now for Cash, or display for income per minute. Mutation multiplies both sides, so the fork gets sharper as you climb S.

Sell when the Cash on screen buys the current best purchasable pump, a needed Pet Egg, or a rebirth you already planned. Display when the fish is Hole or Venom and you are not blocked on a pump. Diamond can go either way. Gold almost always sells, because two times a common fish is still a common fish.

Do not display a backpack of Gold just to feel rich. Aquarium slots and display stands are cheap to expand one level at a time, but they are not an excuse to hoard 2× commons. The Lava Aquarium sits in the Cthulhu endgame with Gold Cthulhu, Cthulhu Coins, and Tickets — a destination tank, not a reason to skip Hole hunting.

What mutations do not replace

Mutations do not replace pumps. A Hole fish funds a pump; it is not a pump. They do not replace pets. Equipped pets multiply Water while you click; mutated fish multiply the Cash that pays for clicks to go further. Keep slot ranks on the pets tier and collection notes on the pets collection guide.

They also do not invent a species list. Fish rarity stacks with mutation, but this page will not publish a fake bestiary. The MythicFish code grants a random fish; community reports mention Mosasaurus or Narwhal. Log the mutation on whatever you roll. A common mutation on a reported mythic is still a mutation rank, not a new S row.

Auras, walk speed, and other hub-stand extras stay quality-of-life. Spend on them after the weather window, not during it.

Session checklist

1. Watch for Poison or Black Hole.
2. Drain hard for four minutes.
3. Protect Hole and Venom.
4. Sell Gold, most Diamond, and anything that buys a pump.
5. Check HUD Pumps before you celebrate.
6. Redeem codes such as MythicFish when you are already at a tank, not in the middle of a weather scramble.

Broader ranks live on the tier list hub. Permanent Water and Cash multipliers after a reset are on the rebirths guide. Day-one clicks still belong on the beginner walkthrough and the guides hub. The players hub is the collection map if you forgot which stand is which.

When Black Hole weather is up, stop sightseeing and drain. A four-minute Hole window is worth more than a backpack of Gold fish. Log the weather, sell the rest, and let 20× do the math.