The Halibut Harpoon is a hybrid tool in Fisch that works as both a standard fishing rod and a harpoon gun, and it was added in the version 1.97 update. To unlock it, you have to track down the Dr. Monty NPC, answer three riddles correctly, and then clear two long fishing quests centered on pufferfish.
Quick answer: Travel to the Depths POI, reach GPS 461, -2002, -13150.2 in the Outer Deep, enter the first dome-shaped building through the glowing window, and answer Dr. Monty with Hubbermeisterchen, 13,388.82 C$, and Orange. Then finish both pufferfish catch quests.
Where to find Dr. Monty in the Outer Deep
Dr. Monty hides in a secret laboratory buried in the Depths. His lab sits on the northern edge of the map inside a cluster of blue houses and buildings, marked by a Beacon 1P-2 tower.
461, -2002, -13150.2. You will arrive at the group of buildings that make up the site.Dr. Monty riddle answers
You must answer all three riddles correctly in a row. A single wrong choice sends you back to your spawn point, forcing the full trip to the Outer Deep again. Pick the exact answers below.
| Question | Answer |
|---|---|
| The goggobites gather for what? | Hubbermeisterchen |
| What is the base value of a Sparkling Shiny Aether Pufferfish? | 13,388.82 C$ |
| What is my favorite color? | Orange |
Once all three answers land, Dr. Monty hands over two quest stages that must be completed in order.
Quest 1: Catch and return the standard pufferfish
The first stage asks you to catch and return 10 of each pufferfish species listed below. Each one has its own location, bait, weather, season, and time-of-day requirements, so line up the conditions before you cast. Prepare the bait in advance to avoid backtracking.
| Fish (Location) | Bait | Weather | Season | Time |
|---|---|---|---|---|
| Pufferfish (Roslit Bay / The Ocean) | Seaweed | Any | Summer | Any |
| Flying Pufferfish (Above The Clouds) | Seaweed | Any | Summer | Any |
| Blight Pufferfish (Toxic Grove) | Weird Algae | Any | Any | Any |
| Pufferflute (Crystal Cove) | Flakes | Clear | Autumn | Day |
| Pyrite Pufferfish (Volcanic Vents) | Shrimp | Any | Autumn | Night |
| Carrot Pufferfish (Carrot Garden) | None | Rain | Spring | Any |
| Mustard (The Ocean) | Seaweed | Rain | Summer | Any |
Quest 2: Perfect Catch pufferfish with specific mutations
The second stage keeps you on pufferfish, but every objective demands a Perfect Catch of a pufferfish carrying a set mutation, with 10 required per mutation. The reliable way to force each mutation is to equip its matching rod before you fish. Use the pairings below.
| Mutated Pufferfish | Rod to equip |
|---|---|
| Wrath Pufferfish | Rod of The Zenith or Dead Man’s Rod |
| Rotting Pufferfish | Splitbranch Twig |
| Abyssal Pufferfish | Abyssal Specter Rod or Rod of the Depths |
| Lost Pufferfish | The Lost Rod |
| Celestial Pufferfish | Celestial Rod |
| Aurulent Pufferfish | Auric Rod |
| Crystalized Pufferfish | Crystalized Rod |
| Heavenly Pufferfish | Heaven’s Rod |
| Sunken Pufferfish | Sunken Rod |
| Greedy Pufferfish | Rod of the Eternal King or Scurvy Rod |
| Bellona’s Fury Pufferfish | Bellona’s Waraxe |
| Mastered Pufferfish | Ruinous Oath |
| Sandy Pufferfish | Sand Castle Caster |
| Rainbow Cluster Pufferfish | Rainbow Cluster Rod |
| Honey Pufferfish | Sweet-Stinger |
| Solarblaze Pufferfish | Wicked Fang Rod or Fang of the Eclipse |
| Sanguine Pufferfish | Sanguine Spire |
| Tainted Pufferfish | Bloomspire: Twisted Toxins |
| Tidal Pufferfish | Rod of the Forgotten Fang |
| Brined Pufferfish | Brine-infused Rod |
| Mythical Pufferfish | Mythical Rod |
| Phantom Pufferfish | Eidolon Rod |
| Atlantean Pufferfish | Trident Rod |
| Lunar Pufferfish | Astral Rod or Event Horizon Rod |
| Lucid Pufferfish | Lucid Rod |
Note: These objectives require a Perfect Catch, not just any catch. Landing the bar in the perfect zone is what counts toward the tally, so a normal catch of the correct mutation will not register.
Confirming the quest is done
Each objective updates as you return the required pufferfish to Dr. Monty, so track the counter climbing toward 10 for every entry. After both stages read complete, Dr. Monty rewards the Halibut Harpoon, which you can then swap between rod and harpoon modes at will. Clear Quest 1 in full before Quest 2 unlocks, and keep the right bait and rod equipped for each target to avoid wasted casts.
