Five boss fights are never required to reach the ending. Two of them are worth doing on every playthrough: the Blue Shark, because it unlocks the grill, and the Goblin Shark, because it is the most valuable single sale in the game. The Old Pike and the Sunfish are cheap practice and count toward Collector, and Bing Bong is an Easter egg.
Do not mix them up with the Tuna. It is summoned with a shop lure like these, but the Albatross cannot appear without a dead Tuna, so it is part of the Island 4 story.
Rules that apply to all of them
Every one of these fights has an escape timer: the white bar under the health bar, about 180 seconds for the lure bosses. If it empties, the boss swims off and you have to buy another lure. All health values below are for Normal solo play. Easy uses 75% of the health and Hard 125%, and every extra player in the lobby raises boss health.
The Old Pike and the Sunfish (Forest, Island 2)
Both come from the same Beginner Boss Lure ($40), and each cast is a coin flip: half the time The Old Pike bites, half the time the Sunfish. If you get the one you did not want, kill it and buy another lure. The Sunfish also bites very rarely on the ordinary Beginner Lure.
The Old Pike has 1,000 health. It flops in close and swings its tail; the hits hurt but rarely kill if you already own a Shotgun. There is no pattern to learn: keep moving around it and keep firing through the flops. It sells for $80. Its real use is practice. If the Giant Piranha keeps beating you, this fight teaches you to read a boss and manage the escape timer without spending your Leech Bait.
The Sunfish has 1,500 health and makes wide, heavy charges along the shoreline. Back out into open ground so it cannot pin you against rocks or trees, and shoot its broad body between charges with a Pistol or Shotgun. Skip Dynamite here: at close range the blast hurts you as much as the fish. It sells for only $50, but it is a Fishipedia entry you need for Collector.
The Blue Shark (Desert, Island 3)
The Standard Boss Lure ($280) summons it. It has 2,300 health and lunges in fast straight lines, so circle tightly around a pair of palm trees while you fire an upgraded SMG or Shotgun. Do not sell the body for $300: give the whole shark to the Grillmaster and he unlocks the grill, which cooks everything you sell afterwards up to 1.5x. Do this before the Pufferfish. The full walkthrough is in the Island 3 guide.
The Goblin Shark (Volcano, Island 5)
Buy the Scientific Boss Lure ($5,800) at the military supplies and cast from a stable ledge. The ordinary Scientific Lure will not bring it up. The Goblin Shark has 7,500 health and lunges suddenly with its long jaw; take each hit seriously and keep your health topped up.
Strafe along the shore so it never gets a straight line at you, and fire when it recoils from a missed lunge. A maxed Assault Rifle is best; a fully upgraded SMG or Sniper Rifle also works. Never try it in melee range.
The payoff is the best in the game: about $6,200 raw and roughly $9,300 after cooking it in lava, before any kill-score bonus. The Grillmaster also accepts it in place of a Blue Shark if you skipped that fight.
Bing Bong (Desert, Island 3)
Bing Bong is an Easter egg. Walk to the group of palm trees in the middle of the Desert island and check each one; the right palm, a noticeably slanted one, shows a purchase prompt for a Coconut at $350. Equip the Coconut as bait and cast on Island 3.
It has 2,000 health but hits for 75 per contact, which kills quickly. Fight it from open ground, keep your distance and use an SMG or other ranged weapon. A second player makes it far safer. Stock food and ammo before you spend the Coconut.
The body sells for $300 and counts as an endangered creature. Bing Bong is not one of the 62 Fishipedia entries, so it is not needed for Collector. A red Drip form exists, but nobody has published its odds, so expect to buy several Coconuts if you are hunting it.
Next: the drip creatures and the Fishipedia, where these optional catches count.
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