Each sheep fits into the one below. 3 stackable sheep.

sheep_stack.stl - The three sheep.

sheep_stack.py -  The SolidPython code that made this.

sheep.stl  - the original file used as input for sheep_stack.py

This was designed with SolidPython and can be modified by changing sheep_stack.py. After changing generate the intermediate openscad with:

python3 sheep_stack.py

then create the stl with:

openscad -o  sheep_stack.stl  sheep_stack.scad

The script outputs the three sheep as seporate files, the .stl included here was the export after assembling them in PrusaSlicer.