The Halibut Harpoon is a hybrid piece of equipment in Fisch that works as both a harpoon gun and a standard fishing rod. Unlocking it means tracking down the Dr. Monty NPC, answering three riddles without a single mistake, and grinding through two long Pufferfish quests. Get one riddle wrong and you respawn at your set point, forcing a full trip back to the lab, so the answers below matter before anything else.
Quick answer: Travel to the Outer Deep in The Deep at coordinates 461, -2002, -13150.2, enter the first dome house through the window, talk to Dr. Monty, and answer Hubbermeisterchen, 13,388.82 C$, and Orange. Then finish both fishing quests to receive the Halibut Harpoon.
Where to find Dr. Monty in the Outer Deep
Dr. Monty hides in a secret laboratory in the Outer Deep, on the northernmost edge of The Deep. Head to the Depths point of interest, then travel underground to GPS coordinates 461, -2002, -13150.2. You will arrive at a cluster of blue houses and buildings, including a Beacon 1P-2 tower.
All Dr. Monty riddle answers
Answer all three correctly in one sitting. A single wrong choice ends the interaction and sends you back to your spawn point, so match each response exactly as written below.
| Question | Answer |
|---|---|
| The goggobites gather for what? | Hubbermeisterchen |
| What is the base value of a Sparkling Shiny Aether Pufferfish? | 13,388.82 C$ |
| What is my favorite color? | Orange |
Quest 1: Catch seven Pufferfish species
Once the riddles are cleared, Dr. Monty hands over the first fishing task. You need to catch and return 10 of each Pufferfish variant listed below, and each one has its own location, bait, and catch conditions. Prepare the right bait ahead of time to avoid backtracking.
| Fish (x10) | Location | Bait | Conditions |
|---|---|---|---|
| Pufferfish | Roslit Bay / The Ocean | Seaweed | Summer, any weather, any time |
| Flying Pufferfish | Above The Clouds | Seaweed | Summer, any weather, any time |
| Blight Pufferfish | Toxic Grove | Weird Algae | Any season, weather, and time |
| Pufferflute | Crystal Cove | Flakes | Autumn, clear, day |
| Pyrite Pufferfish | Volcanic Vents | Shrimp | Autumn, any weather, night |
| Carrot Pufferfish | Carrot Garden | None | Spring, rain, any time |
| Mustard | The Ocean | Seaweed | Summer, rain, any time |
Note: A few of these depend on specific weather and season windows, so line up rainy Spring for the Carrot Pufferfish and a clear Autumn day for the Pufferflute before you head out.
Quest 2: Perfect Catch mutated Pufferfish with the right rod
The second task only uses Pufferfish, but every catch must carry a unique mutation, and each one must be a Perfect Catch. You need 10 of each mutation. The fastest way to force a specific mutation is to equip the rod tied to it, then land clean Perfect Catches until the counter fills. The pairings are below.
| Pufferfish mutation (x10, Perfect Catch) | Rod to equip |
|---|---|
| Wrath | Rod of The Zenith or Dead Man’s Rod |
| Rotting | Splitbranch Twig |
| Lost | The Lost Rod |
| Abyssal | Abyssal Specter Rod or Rod of the Depths |
| Celestial | Celestial Rod |
| Crystalized | Crystalized Rod |
| Aurulent | Auric Rod |
| Heavenly | Heaven’s Rod |
| Sunken | Sunken Rod |
| Greedy | Scurvy Rod or Rod of the Eternal King |
| Lucid | Lucid Rod |
| Lunar | Event Horizon Rod or Astral Rod |
| Atlantean | Trident Rod |
| Phantom | Eidolon Rod |
| Bellona’s Fury | Bellona’s Waraxe |
| Mastered | Ruinous Oath |
| Sandy | Sand Castle Caster |
| Rainbow Cluster | Rainbow Cluster Rod |
| Honey | Sweet-Stinger |
| Solarblaze | Fang of the Eclipse or Wicked Fang Rod |
| Sanguine | Sanguine Spire |
| Tainted | Bloomspire: Twisted Toxins |
| Tidal | Rod of the Forgotten Fang |
| Brined | Brine-infused Rod |
| Mythical | Mythical Rod |
How to confirm the Halibut Harpoon unlocked
Return every required fish to Dr. Monty as you complete each objective. Once both quest sets read as finished, he awards the Halibut Harpoon. Because it is a harpoon gun and not a standard rod, it lands in your Equipment Bag under the Harpoon Guns section rather than your rod list. Open that section and equip it to start using it against roaming fish or as a regular rod at will.
If an objective refuses to update in the second quest, the most common cause is a catch that was not a Perfect Catch or a fish without the exact mutation the step demands. Equip the matching rod, aim for clean Perfect Catches, and the counter will move.
