Stage 5 of 6
Island 5: the scientific lure, the whale and the final boss
The volcano island sells the top lure and the assault rifle. Five creatures buy the whale bait, the whale drops the fin, and the lava turns it into the final fight.
Checked against Patch 1.0.11.

Your route through Volcano Island
3 people are here, with 7 stations, and the shore drops footsnail, radio and seagull. The island ends with the Mutated Bowhead Whale. Every detail of the island is in the islands lookup.
Buy what this island adds
New here: Scientific Lure ($500), Scientific Boss Lure ($5,800), Assault Rifle ($20,000). Whether the Scientific Lure is worth it now: Which lure to buy. Whether to buy the Assault Rifle: Which weapon to buy.
Earn the boss bait
The whale quest-giver wants any 5 creatures and hands back the Fish Bucket. The whole chain.
Use the stations
Boat motor upgrades, Boat radar, Bullet damage upgrades, Melee sharpness upgrades, Reel of Fortune slot machine, Roulette table, Weapon attachments. Every ladder and price is in the upgrades lookup.
Decide about the casino
A roulette table and the Reel of Fortune. Is roulette worth playing, and which island to spin on. What each spin can land on is in the skins lookup.
Beat the Mutated Bowhead Whale
Hand any 5 creatures to the whale quest-giver for the Fish Bucket, hook the Bowhead Whale with it, kill it, then drop the dead Bowhead Whale into the lava. 38,000 health on Default, five minutes before it leaves. How do I hook the whale and beat the final boss? How its health comes off: How is damage worked out, and what does a kill bonus do? Its stats are in the creatures lookup. What the Whale Fin is for: What do the boss drops do?
Finish the story
The whale quest-giver wants Whale Fin. The whole chain.
Then: After the credits
With the story done, what is left is collection: the journal, every drip variant, the 28 achievements, legendary skins and the single 100,000 sale. Go to the After the credits route.