How to Fish: Giant Piranha fight and summoned fish

How to fight the Giant Piranha

Bring a gun, keep room between yourself and the Giant Piranha, and watch for the smaller piranhas it summons. At half health, the boss becomes temporarily invulnerable and releases another group. Use that transition to move away from nearby fish and reload, then resume shooting when its health can fall again.

The boss has 2,500 HP on Default difficulty with one player and a five-minute encounter timer. Clearing every small fish before returning to the boss can consume that time because its normal waves replenish.

Prepare on Island 2

The Pistol costs 50 and the Shotgun costs 150 at Island 2 shops. Dynamite is also sold there for 25. These are available choices for the first encounter; the SMG and Sniper Rifle appear on later islands.

Complete the Swamp Daughter's bait request for Leech Bait. She specifically advises bringing a gun. Cast with that bait once there is no other active boss.

What the small piranhas do

Before half health, the routine summoning system allows six living summons in solo play. It checks again after a 15-second delay following a wave and replaces missing fish. Extra players raise that allowance.

At half health, a separate transition releases a group of small piranhas. The routine allowance then rises to 12 in solo play, with a 20-second delay between later checks. The transition's fish are separate from that allowance, so 12 is not a guaranteed maximum number you can face.

Shoot small fish that prevent you from moving or reloading. Once you have room, return damage to the boss instead of waiting for an empty arena that may not stay empty.

Why the boss stops taking damage

The half-health animation includes temporary invulnerability. More shooting during that interval will not lower the boss's HP. The boss and its summons can still be dangerous, so keep moving rather than treating the animation as a break from the fight.

The giant fish lunges toward players and deals damage on contact. Being airborne does not make it harmless. Its movement rules can stop it starting a fresh lunge in midair while its existing body collision can still hit you.

Collect the Skeleton

Take the dropped Giant Piranha Skeleton back for the Island 3 passage request. The progression hand-in needs the trophy rather than one of the small summoned piranhas.