Octophant

Octophant is the rare Limited fish you can still catch today. It lives in the Octophant Hunt area of the Second Sea and needs Golden Worms bait, Clear weather and Summer, with no time restriction listed. The wiki describes a massive creature with strong tusks that sifts the ocean floor.

Its base XP is the first thing to notice: 100,000. Weight is just as unusual. It averages 16,500 kg and can reach 52,500 kg, ranking 59th of 663 fish by maximum weight. At C$1.8 per kg an average catch is worth C$29,700, 65th of the 742 documented fish, which puts it in the top ten percent.

Octophant shares its event pool with Flamangler, Orcanda, Royal Tigerfish, Shrimpanzee and Slurpfloth, all Limited. Among those, Octophant is the one with the enormous XP payout, so it is the natural headline target when the area is open.

Verdict: if you can reach the Octophant Hunt, bring Golden Worms and wait for a clear summer window. With nearly C$30,000 per catch and an exceptional XP payout, it is one of the best returns documented, so it is worth making time for. The only caveat is that Limited fish tend to leave, so treat it as a priority while it is listed as obtainable rather than something to postpone.