Hmmm interesting I can try. It might not be possible if the game developer expressly forbids it in their code. What mob mods do you want me to try to add? Edit: I added many of the nodes from Backrooms to a backrooms group like I usually do, and addeth that group to the animalia spawn, but nothing spawned. My suspicion is that Creatura Mob API which this mod uses depends on code in minetest Game which is not included in Backrooms. I've got some questions out, will let you know if I find out anything, but this will not be an easy fix if at all. Still working on it though.
I got it working sort of. If you fly, you can see that the game is divided into many layers. You start at the bottom layer. I was able to get animalia working, and saw bats spawning on level 1 because I was "underground". To get animal world mod working I would have to get default and buckets mods added which could be a problem. I also did see rats and owls in some levels. So as long as the mob mod doesn't depend on other minetest game mods, I think it will work if I spawn the mods at heights that the game is played in. So if you let me know the mobs you want to see, and those mob mods don't depend on minetest game mods, I should be able to add at least some support for them. Otherwise if you add backrooms & animalia you should see some mobs.