Pufferfish Prime Boss Guide — The Island 3 Wall, Phase by Phase

How do you beat Pufferfish Prime?

The first true wall of the run guards the Deep Abyss in three escalating phases, and it is a gear check pretending to be a skill check. Phase one is a classic big-fish line duel, phase two opens inflation windows that only dynamite punishes, and phase three is a leech-drone escort fight straight out of Island 2. Minimum comfortable kit:

• SMG for the drone phase — the shotgun’s reload gets punished hard here.
• At least 3 dynamite — one per inflation window, plus one for panic. On Hard, carry 5.
• A cooked stack in the pantry — the fight is long enough that hunger kills more crews than the boss does. The grill rotation covers the batch habit.
• Deep troll rig on the rod for phase one, if you have it.

Phase 1 — The Duel (100% → 66%)

It opens as a classic big-fish duel: it charges the line, runs, and tires. The one rule everyone breaks: do not reel during the charge. Let it take line, lift the rod tip, and reel only when it turns. Two or three clean cycles and the health bar moves. Shooting it during this phase does almost nothing except waste ammo and teach you bad habits.

Phase 2 — Inflation (66% → 33%)

At two-thirds health it surfaces and starts inflating. Each inflation cycle ends in a pressure burst that damages everything in the water ring around it. The safe window is the moment before the burst: throw one dynamite as the spikes straighten, and the internal damage carries into the next cycle. Three clean dynamite cycles skip most of this phase.

• The tell: spikes point outward before a burst, inward before a recovery. Outward = throw, inward = reel.
• On Hard (patch 1.0.8+) the inflation telegraph gained roughly 0.4 seconds — it’s more forgiving than it looks. Trust the spikes, not your panic.
• Anyone on the boat should be healing the gunner between cycles, not fishing.

Phase 3 — The Swarm Escort (33% → 0)

Below one-third, it calls leech drones — the same swarm AI from Island 2, but spawned mid-fight. This is a pure crew-coordination check: the gunner holds the deck, the angler keeps the line tight on the boss, and the chef grills between waves. If your lobby has fewer than three people, swap between line and gun on the wave rhythm — the boss pauses to spawn, and that pause is your rotation window.

What is the trophy actually worth?

The trophy carcass sells for a serious stack of chips (check the fishipedia for the current ballpark), and the first clear drops the Trophy Hunter achievement. Sell the trophy at the high-roller table, not the dock — the drip premium applies to boss trophies too, and it’s the single largest legal income event in the game. The full sale math is in Casino Economics.

One variant worth planning for: the missable Return to Sender achievement wants this fight with zero dynamite — the pin-and-reel patience route, run on Easy with full gear (see the achievement hunt).

Where does this fight sit in the gauntlet?

It’s the dynamite-discipline check of the four: the Leech Matriarch tested coordination on Island 2, the Reef Tyrant tests gear order next, and the Golden Leviathan tests greed at the end of the line.