The Pufferfish is the main boss of the Desert Island and one of the biggest difficulty increases in How to Fish. It attacks using fast rolling charges before growing larger and leaving purple poison around the island later in the battle.
You need the Carrot from the Tourist to summon it. Defeating the Pufferfish and returning its Fin will unlock the coordinates for the next island.
If you need help reaching the boss or completing the islands quests, check out our full Desert Island guide.









