Unmarked warships
While obviously no sea creature as such, unmarked warships are as much of a threat on the high seas as any Picaroon or Sea hag. Bristling with weaponry, the high rails of these warships protect and hide their crew and cargo from view. Four plain canvas sails and an array of oars provide propulsion in gale or doldrums, but neither bear identifiers. Every visible crewman aboard is usually clad in cream shirt, brown breeches, and bared feet, and the construction of the decks prevent any given command from being overheard.
These enigmatic vessels often sail the turbulent waters of the Phocian Reaches, their ends unknown.