Of course, there's no shortage of beach-flavored horror novels to read while you're on vacation. Most of which are of the creature-feature variety. So there's a lot of stuff out there.
If you're a horror author, this can be incredibly frustrating if you want to find something new and frightening to dazzle a reader with.
Now the sea is filled with predators, terrifying and cute. From seals to sharks. And the vast majority of the particularly nasty ones already fill books. From the sizes they naturally come in, to giant versions capable of swallowing people whole.
Of course, there's giant sharks of all kinds. Then you have large squid. Even giant crabs have been used.
Reaching back into pre-history is also a wealth of strange and deadly creatures. Most common of these is the giant shark, Megalodon. Also a bit popular are Mosasaurs and Liplurodons. Of course, these aren't the only prehistoric predators which could find a home in sea-based horror. There are creatures such as Dunkleosteus and giant sea scorpions, but as things become lesser known you get more reactions of "Huh?" as opposed to "Oh shit!"
Not that people are really put off by that. Especially over at the SyFy channel where they're happy to throw up movies about killer Lampreys. You can even find horror based on a parasitic louse that eats and replaces the tongue of its host fish.
And, I am legally required to mention Cthulhu in a post about sea monsters.
There are lots of home-made sea monsters you can find as well. Sharktopus is the first thing to come to mind, and a good example of a combo monster. There are also alien creatures, as well as man-made creatures. Some people even count Kaiju such as Godzilla and the beasts of Pacific Rim as sea monsters.
So what's a horror writer to do? Pump out yet another re-hash of JAWS? Pick some obscure creature from Earth's history such as Livyatan Mellvillei? Maybe play the role of a sea-based doctor Frankenstein and plop down the lobster-shark?
No idea, to be honest. We'll just have to see what happens when you see a water-based horror novel with my name on it.
Did I miss any? What are some of your favorite sea monsters? Feel free to drop them in the comments below!