Kraken

"If you can imagine a hyper intelligent octopus the size of a dragon with magical control over currents and microclimates… that’s basically a kraken. According to the Sailorite accounts, they eat ships."Cassiopeia Stargazer-Greenskin describes a Kraken to Hugo Dargent.
Krakens are monstrous intelligent octopuses native to West Star. They feature the Sailorite Holy Text as a monster encounted by explorers on the Plane of Water. They never stop growing, but eventually they collapse under their own size when the water can no longer support them and they suffocate.   According to the Galleon's Scrivener, Mister Turkey, this is only the third-most common cause of death for a Kraken. The second is dying in the war against the Aquatic Dragons and the first is being eaten by larger Kraken.
Elemental Origin
Aqueous (Plane of Water)