Swallow Dungeons

In the ocean, there can be different types of whales that contain dungeons that vary based on the breed. The bigger the whale, the bigger the dungeon. All whales can be befriended but only orcas will stick around, they can act as a portable room in the ocean. You can befriend/tame with a Totem Of Benevolence (gives strength, saturation, luck, and resistance) which is acquired from an evil rare whale or a beached whale. You can even watch whales eat things like krill and plankton from far with a spyglass!

https://imgur.com/a/seuey0j