Roman Chumak writes:
Morphle is tiny Blender add-on that creates an object containing shape keys from selected objects vertices positions.
Select some objects, click Morphle! and in the World Origin the Morphle object will be created. It appears as an object with the most vertices from the selected ones. In shape keys of Morphle object you will find names of all previously selected objects and can interpolate between their vertices positions. From then you can make instances of child object or spawn particles from Morphle’s vertices, delete/hide polygons and edges, animate shape keys and enjoy your beautiful morphs.