(n.) Any large sea animal.

Bassalia Loch Ness monster abyss abyssal zone alevin bathyal zone benthon bottom waters bottomless depths cetacean dolphin fingerling fish fry game fish grilse ground inner space kipper man-eater man-eating shark marine animal minnow minny nekton ocean bottom ocean depths ocean floor panfish pelagic zone plankton porpoise salmon sea monster sea pig sea serpent sea snake shark smolt sponge the deep the deep sea the deeps the depths trench tropical fish whale