Since I see a lot of fun potential with this mod concept, here are some ideas I think would be cool to secure, contain and protect.

- Some kind of cursed object, like a cube or something, that from time to time spawns a ghost that can go through most walls, except some very expensive kind of wall. It would be ideally unkillable, so that the player has to just survive for the time the ghost is spawned.
- A Pandora Box that, when damaged, opens and releases some very long bad weather or colony wide effect, like toxic fallout or drone
- A creature that emanates an aura of disconfort that gives pawns negative mood and makes their mental breaks exclusively about releasing it.
- Something that summons meteors, that fall in random spots a certain radius around it.
- A very kind, collaborative and useful creature, that becomes an aggressive monster when a pawn has a mental break close to it.
- An object/creature that pollutes the area around it, creating toxpacks and polution.
- An object/Creature that slowly makes the terrain around it into water.
- Some dangerous creature that needs a lot of energy to keep dormant, that rampages around when it wakes up.
- A creature that gradually damages the structures built around it.
- A creature that drains psychic heat/accelerates meditation on psycasters on the surrounding area but, after a threshold, it enters an aggressive state and tries to escape.

I ultimately don't know the limits of what is possible in modding and I recognize some of this suggestions could be impossible or too much work. I also know that I'm not entitled to you actually doing any of them. I this this is mostly to show that there is demand for what you are doing, and it would be very well received, if you choose to keep doing it :D