Hostiles

You want to keep hostiles fantasy, how about leviathan for oceans. Can be pretty large, but not huge. Only appears when water is past certain depths. They attack boats/rafts. Dolphins attack them, similar to cats/spiders, wolves/skeletons. Would just like to see more varity hostile water creatures. Too many drowned. Guardians are confined and Easy to avoid. Swamp Bogs. Similar to Swamp Thing. The zombie/husk of shallow water swamps. But instead of just walking around, it has a lilypad piece that shakes when you're near it, but if you don't notice, it springs up and attacks