Aquatic creatures

I use lot's from all over. From kraken's to selkie's and the mer-peeps. Serpents are there, giant island turtles and other sea creatures, because the sea is vast and full of weird. And I happily throw in Gamera like giant turtles and other kaiju. Swamp things and lizard folk to wander swamps and marshes. Anything that can be put into 'Giant' category, even if they were small to start with. I expand things out, like octopi and squid in swampy jungles and rivers. Croc's and gators that can tip even very large ships.

 

Selkies I think have a lot of potential. Also, going off of Orc Knight's post, DRAGON TURTLES! Kraken are a staple and so are Sea Serpents but honestly I think the best way to make an aquatic monster is to look at real-world fish and ask yourself, "what would happen if this organism was magical?" The freakier the fish, the more monstrous the monster!