Hello fellow pathfinders, I am currently DMing a Skull and Shackles campaign and the party is nearing level 10. One of the players, a cavalier, has expressed interest in the Mammoth Rider prestige class, but with an aquatic mount. He is currently riding a modified swordfish that he and I brewed up together, but not sure what animal would be an appropriate / balanced huge aquatic companion if he does decide to try that route. Anyone have some advice on which creatures would lend themselves to such a sweet killer concept, or should would simply "bulking up" his swordfish to huge size be the way to go? Thanks in advance!