Spider Crab Boss Guide (The Culprit) — How to Fish
Updated 2026-08-26
How to summon and beat the Spider Crab, the first boss in How to Fish: the Empty Beer Can quest chain, the Lighthouse Keeper hand-in, and the 'Who stole my beer' achievement.
Who is "The Culprit"?
The first boss of How to Fish is the Spider Crab, fought on the Lighthouse island. Players call it "The Culprit" because the Steam achievement for the fight — 'Who stole my beer' (89.7% global unlock rate) — reads "Find and kill the culprit, and bring it to the lighthouse keeper." It is a story boss: you cannot progress to the second island without it.
How to summon the Spider Crab: the Empty Beer Can chain
The Spider Crab ignores every normal bait and lure. Per the KeenGamer walkthrough, the summon works like this: 1. Earn some money from your first catches (Ham catches Brown Crab and Shrimp; Hot Dogs catch Rock Crab and Lobster). 2. Buy a Beer Can from the island shop. 3. Give the Beer Can to the Lighthouse Keeper. 4. He drinks it and hands back the Empty Beer Can. 5. Equip the Empty Beer Can as bait and cast to summon the Spider Crab. The most common mistake here is casting a normal, unopened Beer Can — only the emptied can the keeper hands back works.
The fight itself
This is the tutorial boss and the game expects you to win it with starting-tier gear. Buy a basic weapon from the Lighthouse shop before casting, keep moving, and back off when the crab commits to an attack. There are no phases or special mechanics to memorize — if you are struggling, sell a few more catches and upgrade your weapon first; nothing about the quest expires.
After the kill: do not skip the hand-in
Defeating the Spider Crab is only half the quest. Feed the boss meat to the Lighthouse Keeper to complete the hand-in — he rewards you with the boat keys, which unlock the boat and the route to the Forest island. The achievement fires on the hand-in, so if 'Who stole my beer' did not pop, the drop is probably still lying where the boss fell. Physics can scatter items, so search the area before re-fighting.
Using this fight for the 'Easy' achievement
'Easy' asks you to kill a boss within 10 seconds. The practical route is to learn an early boss like this one on a normal clear first, then return with a fully upgraded weapon and start dealing damage the instant the fight begins. Early bosses have the lowest health pools, which makes them the most consistent targets for the timer.
How to apply this guide safely
Begin with “Who is "The Culprit"?” and compare it with the objective, inventory, and controls shown by your installed build. Do not change several variables at once. If the guide concerns progression, complete one dialogue or hand-in and confirm the objective changed before sailing away. If it concerns combat, test the control or equipment choice on an ordinary encounter before spending a boss trigger. If it concerns troubleshooting, preserve the save and start with reversible checks such as restarting the session and verifying files.
Keep a short run record with the game version, solo or co-op state, host identity, starting objective, relevant equipment, steps taken, and outcome. Physics, network state, and retail patches can make two attempts look different even when both players describe them honestly. A controlled record lets you identify which condition changed. It also gives the developer a useful reproduction if the result points to a defect rather than a missed quest step.
Evidence and version check
This article uses KeenGamer — How to Fish: Complete Walkthrough & All Fish Locations, Steam Community Achievements — How to Fish. Official store text and developer announcements establish supported features and broad progression. Steam achievement wording establishes that a named action exists, but it does not prove an exact coordinate, probability, price, damage value, or hidden timer. Community discussions can reveal a repeated problem and possible workaround, but one reply is not treated as a universal mechanic. Where evidence stops, the guide uses cautious testing steps instead of inventing a precise answer.
Before relying on an older route, check the Steam news and discussion dates against the updated date at the top of this page. Prefer the current in-game objective when it conflicts with a video or forum post. Avoid unknown executables, replacement saves, cheats, or destructive file edits offered as shortcuts. A legitimate workaround should be explainable, reversible, and testable without surrendering account credentials or deleting the only known-good save.
Completion check
Finish with “Using this fight for the 'Easy' achievement,” then verify the result in the system that matters: quest log for progression, inventory for items, Steam for achievements, or a repeatable symptom check for a technical fix. Do not treat a visual animation alone as proof that the save registered the event. Wait for a normal transition and inspect the state before selling items, changing hosts, or starting another objective. If the result differs from this page, send the URL, build number, exact steps, and observed result through the contact page; that evidence is how we correct guides without turning uncertain reports into false facts.
Sources & Evidence
Claims are backed by the following sources. Unknowns are marked explicitly.
- KeenGamer — How to Fish: Complete Walkthrough & All Fish LocationsThird-party / Tier 4Checked 2026-08-26
- Steam Community Achievements — How to FishCommunity / Tier 2-3Checked 2026-08-26