So, I'm going to copy-paste the most recent entry from my dream diary, with a few edits so that it's readable by people who don't know me on a quite personal level.
I think I had Super Mario Odyssey on my mind for this one. I was inside Bowser’s castle with my cousins, as well as my mom and I think one other person. The castle was absolutely massive, and split into many, many different areas. The base area where we were set up for the most part had a certain haunted house aesthetic to it. Large amounts of treated wood, fancy rugs, dim-ish lighting, and a bunch of doors which we never thought to check. I was on the track to complete the game, then backtrack and get all 120 stars. I ended up going solo to the lowest and by far largest area of the castle, which I believe was called Bowser’s Keep. It seemed very familiar, like I’ve been there before; perhaps it was the semblance to… whatever the lava area was called in Metroid Prime. Or maybe it’s the lava caves from Wallace and Gromit: Project Zoo. It was a winding labyrinth, suffice to say, composed of a very dark-colored stone material, smoothed out and carved with intricate designs. The lower areas were cavernous and contained lava, and if you weren’t careful in the few open parts of the upper areas you might fall all the way down. I believe the area ran down a fair portion of the underside of the castle, which was hanging in… who knows where. Bowser’s keep lead to the bottom.
The area where the adventure of the night took place was actually a place I'd seen in my dreams before. A rather tall, almost cubical part of a building with a large common area in the center and tiered walkways at the front, stairs and elevators leading up to each tier being positioned at the corners. These tiered walkways would also stretch to the outside, but were separated from the outside world by glass. Inside this room, the floors were made of polished white tiles, with the occasional black tile. The back wall had a pair of staircases with fancy banisters which went up from each side, met in the middle, and split off on either side again, leading up to a pair of small landings which went back to the very end of the large room. Between them was a large decorative pool of water, which contained the highlight of the adventure. The landings lead to other areas in the castle, the one on the left (from inside the room) leading to the haunted house area where we had more or less set up camp.
When we entered the room, (from the landings in the back) there was a very large piranha plant rising up out of the water, but it didn’t attack us, it talked to us. “Hey. Don’t even think about swimming in the water here. There’s something angry hiding in my pipe, and you don’t want it attacking you.” It was about that time that an enormous fish monster with a harpoon sticking through it leapt out of the waters and began attacking us. The details of the fight and how it was executed escape me, but I remember a few important points. The monster proved hard to defeat, at one point my cousin attacked from the stair landing on the right and got swallowed, and I finished it off with a blow to the skull. I used some form of weapon, I remember it being spear-like, but I don’t remember what exactly it was. When the monster died, it returned my cousin as well as... Some other person cobbled together from memories, a girl I might have seen at a big fair that gets held every year where I live. I guess it upchucked the two of them…? Anyway, we greeted the newcomer and my cousin emptied the tank, allowing us to deal with whatever was inside the piranha plant’s pipe, and after that we were rewarded with a star for our efforts.
After that, we were sent back to the room where we were set up, and our new friend came with us. We complimented each other on our performance in the fight, she thanked us for finishing the beast off, I thanked her for putting a harpoon through its chest. After a bit of chatting, we decided we’d meet up in the big common room to decide our next plan of action; probably exploring Bowser’s Keep. There were a lot of people there now that we had cleared out the monster, and the place was bustling. We were starting to get a bit separated, but I noticed my grandma sitting at a table near the front, so I called everyone over to congregate there to work out the plan. I suppose I was the leader of the group. After I greeted her, though, the dream cut out. I honestly find the situation rather intriguing, and I hope to use a similar setting at some point in the future.