See. This is what I love about horror with a slightly toonier style. Because then when somethings carefully rendered it feels... alien. When somethings roughly rendered, when somethings over-rendered... it feels like its not a part of the world.
Hm... the horror of the sea. Junji Ito explored this a few times, once in Gyo and another time in The Thing That Drifted Ashore, which included similar imagery of large unknown sea creatures, well, uh... drifting ashore.