Spider Crab Boss in How to Fish: How to Beat Island 1

Updated 2026-09-02 · Steam How to Fish

How do you beat the How to Fish spider crab? Buy a beer at the lighthouse shop and hand it to the elderly keeper sitting outside; he drinks it and returns the empty can, which works as rod bait. Cast that bait, hook the crab, and fight it on land: it charges in a straight line, and the moment that charge ends it freezes long enough to land several free hits. A knife or maxed brass knuckles is enough. It drops a shell, and the lighthouse keeper trades that shell for the boat keys. Every step of that route is player-reported.

It is the first of the game's bosses. The Fandom walkthrough describes the main route as five island stages and ten bosses, opening with the spider crab and closing with the mutated bowhead whale. Full order on bosses.

Where the spider crab is and how to summon it

The spider crab lives off island 1, the starting island players call Lighthouse Island. It does not wander in on its own; you summon it with a rod bait, like every island boss. The chain, per the achievement guides:

Pick up clams around the shore and sell them until you can afford a rod and a beer.
Buy a beer from the lighthouse shop.
Hand the beer over to the elderly keeper who sits on a bench outside the lighthouse, called the lighthouse keeper or the sailor in different guides. He drinks it and returns the empty can.
Put the empty can on your rod as bait, cast, hook the crab and reel it toward shore.

Prices are player-reported and vary: one sub-hour solo route lists a crab-fishing rod at $3 and a beer at $12, another says $14 covers both. Treat roughly $15 as the entry cost.

One player-tested detail: reel until the crab gets stuck at the shoreline, then stop, because over-reeling pulls it loose and costs you the bait. See bait for every boss bait, of which the empty can is the cheapest. The boss health bar also carries a timer; if it runs out before the crab dies, the boss leaves.

Spider crab attacks and the stun window

The spider crab has one attack that matters: a straight-line charge at its target.

Behavior	What it does	How to answer it
Charge / dash	Runs at you in a straight line, hits on contact	Sidestep, then move behind it
Post-charge stun	Freezes briefly once the charge has finished	Your damage window, hit it here
Wall collision	A charge into the lighthouse wall stops it early	Fight with the lighthouse at your back

Players report dodging and getting behind it rather than trading hits head-on, because the stun only opens once the charge has committed. Standing close to the lighthouse so the crab crashes into the wall is a deliberate speedrun tactic, not an accident.

One achievement guide is blunt about the catch: only this opening boss hands you a free window like that, and every later boss stays mobile, so treat it as a one-off rather than a tactic you carry forward. The giant piranha and pufferfish have to be kited instead. Keep clams in your pockets as the island 1 heal.

Best weapon for the spider crab

Island 1 only sells melee, and the guides disagree over knife versus brass knuckles.

Weapon	Price (player-reported)	Where	Notes
Brass knuckles	Island 1 shop	Island 1	Max the sharpness first; the duo speedrun route summons the boss once both players have them
Knife	$45	Island 1	RubenS says buy it immediately and skip brass knuckles, calling its damage far better on crabs
Shotgun	$150	Island 2	Not available on your first attempt. Maxed, players report 4 to 6 point-blank shots
Sniper rifle	Island 5	Island 5	Late game. Players report a one-shot headshot as it surfaces

Both work. With $60 in clams, take the knife; two players splitting a smaller pot get more total damage out of brass knuckles each. Full pricing is on weapons.

A RubenS tip that applies to every boss: when something bites, do not drop your catch manually, because the game snaps you back to fists. Press your weapon hotkey instead and it drops the fish and draws the weapon in one motion.

Patch 1.0.11 on 1 September 2026 added toggles for aiming and sprinting plus hold-to-attack, worth setting before the fight. The same patch made your own explosives lethal even with friendly fire off, so stand clear of a partner's dynamite.

Drops, rewards and what the shell unlocks

No patch note covers the crab's loot, so everything in this section is player-tested and comes from the Steam Community achievement guides.

Drop	What it is	What to do with it
Spider crab shell	Quest item and boss trophy	Hand it to the lighthouse keeper for the boat keys
Crab sticks	Meat chunks	Sell them for cash, or eat them to heal

Handing the shell over is what unlocks travel, not the kill itself. If the keeper's conversation stalls, open your inventory first: every boss leaves a distinct trophy, and that is the item the quest giver is waiting on, not the meat. Then buy the radar and follow the green marker to island 2.

Shells are also currency at the Reel of Fortune, which takes drip creatures or boss trophies and rolls the weapon skins available up to that island. That is why the crab gets farmed long after island 1 matters. See skins and islands.

Achievements involving the spider crab

The routes in this table come from unofficial player achievement guides, not from the developers, so treat every method here as player-tested rather than documented.

Achievement	Requirement	Spider crab role
Who stole my beer	Track down the culprit, kill it, and deliver it to the keeper	The spider crab quest itself: beer, can bait, kill, return the shell
Easy	Kill a boss within 10 seconds	Players do this post-game: can bait on the rod, summon the crab, empty a maxed assault rifle into it
GOLD GOLD GOLD	Roll a legendary weapon skin out of the Reel of Fortune	Farmed shells feed the machine, so players grind the crab for rolls

The full list of 28 and the post-game route are on achievements.

Farming the spider crab after the story

Players use the crab as a skin-farming loop. The method, player-tested and reported working on 1.0.10:

Get the island 2 shotgun and fully upgrade its damage.
Buy beers in bulk; that guide budgets around $120 for about ten cans.
Feed each beer to the vendor to get empty can bait.
Summon the crab beside any island's Reel of Fortune. Players report the bait works anywhere, not only on island 1.
Kill it fast, collect the shells, roll them.

A second guide adds that a dead boss corpse can substitute for a drip creature at the machine. Both are community findings, not documented.

Difficulty matters more than gear. Patch 1.0.9 on 24 August 2026 added selectable difficulty: easy gives creatures 25 percent less health and 50 percent less damage, hard gives 25 percent more of each. Sub-hour runners set easy before starting, and players report bosses scaling up in co-op.

Mods that help with boss fights

The game shows a health bar but no numbers. Three Thunderstore mods fix that, all needing the BepInEx pack:

Mod	Author	Version	Downloads	What it adds
BossHP	evansvl	0.1.4	11,708	Exact synchronized boss HP beside the native bar
BossTimer	evansvl	0.1.6	8,649	Exact time remaining before the active boss leaves
BossHpText	lagarbure	1.0.0	1,894	Current and total HP written inside the boss bar

BossTimer turns the crab's despawn timer from a guess into a number. Install steps are on mods.

Sources and last check

Checked 2 September 2026.

Official developer sources: the Steam patch notes for 1.0.9 (24 August 2026), which document the easy and hard difficulty modifiers, and 1.0.11 (1 September 2026), for the aim and sprint toggles, hold-to-attack, and explosives becoming lethal with friendly fire off. Neither patch names the spider crab, so none of the crab's own numbers come from the developers.

Everything else here is player-reported, from Steam Community guides: the bait chain, the reeling behavior, the charge-then-stun pattern and the wall trick, every price including the knife at $45 and shotgun at $150, the shot estimates, the drops, and the farming loop reported working on 1.0.10. Guides used: the two large achievement guides, the RubenS boss and weapon strategy guide of 30 August 2026, the sub-hour speedrun routes, and the skin farming guide. Where guides disagreed on price, both figures appear above. Mod versions and download counts are Thunderstore data as of 2 September 2026 and change often.