Stackable beds sized for Sylvanian Families(tm) and Calico Critters(tm) dolls.
The OpenSCAD files are parameterized and thus changing the dimensions of the bed is easy.
(Design and execution by my daughters.)

Download the STL files, slice them, and print them. Glue the two sections together with acetone or plastic glue.
If you wish to change the bed's dimensions, then download the OpenSCAD files and edit. The dimensions are parameterized and the files documented. Should be straightforward.