This is a 3D printed creature house. This is very similar to the one I played with as a kid that was made out of wood.

Print the six pieces out. FYI STL units are in inches. You will need some sort of glue to assemble the pieces. Personally I used a thin CA glue for the ABS parts which is available at most hobby shops and hot glue for the mesh. Also required is the mesh which is just window screen that is available at many big box or hardware stores. I used metal screen rather than plastic because that is what I had lying around. Either will work fine.