Pufferfish
The third boss.
How the Fight Works
One source describes it as rolling toward the player like a wrecking ball, and recommends shooting twice, then repositioning so it has to chase you again. A gameplay-analysis video adds that fighting it in open ground can turn into a damage race you lose: using trees and solid terrain to interrupt or redirect its approach creates safer windows to shoot, though the physics don't behave identically every attempt.
The boss health bar is visible reading "Pufferfish" in the official gameplay trailer. Two of three guide-site sources also place a "Blue Shark" fight on this same island. See the Blue Shark entry, now separately confirmed by direct trailer footage.
Related
Boss Fights & Island Progression
Islands unlock sequentially: defeat the boss guarding your current island to progress to the next, more dangerous one.
Giant Piranha
The second boss, unlocked after clearing Spidercrab.
Blue Shark
A mini-boss fought on the same island as Pufferfish. Defeating it unlocks grilling.
Island 3
The third island. Fish sell for noticeably more here, and it's home to Pufferfish and the Blue Shark mini-boss.
