The Old Pike
A named boss-style encounter: a large pike fish with its own health bar labeled "The Old Pike."
How to Find It
Reportedly summoned with a Beginner Boss Lure on Island 2, per Game8.
Seen directly in the official release trailer: a health bar reading "The Old Pike" while the player fights a large fish near a forest/lake shore (not the tropical-island setting of Spidercrab/Giant Piranha/Pufferfish/Blue Shark), consistent with a "Forest" island setting. Its exact progression role (required vs. optional) is still not confirmed, but Game8 independently places it on Island 2 alongside Sunfish, which is new information not previously linked.
Related
Boss Fights & Island Progression
Islands unlock sequentially: defeat the boss guarding your current island to progress to the next, more dangerous one.
Forest
The second island, reached by boat rudder. Home to a leech-collection quest, Giant Piranha, Sunfish, and The Old Pike.
Sunfish
A reported Island 2 boss, summoned with a Beginner Boss Lure alongside The Old Pike.
Beginner Boss Lure
Boss bait for both Sunfish and The Old Pike on Island 2.