something strange is if you go to a shark when you are a catfish, it teleports you to the room next to the plant. It doesn't matter if there is a shark there or not, just interacting with the seat teleports you.
Also, after you get all the main pillars you can become a catfish, then you need to talk to the big fluffy thing in the lobby to be teleported to the catfish area. I think you can go back to it whenever you like.