How to merge/morph/transform an object into another object in Blender? The letter "A" is walking from left to right and slowly evolves into the letter "B".

How is this done?


Here's my search process:


"Blender merge one rig into another"
returned articles on how to combine various armatures. 
"Morph blender character in timeline" returned a beautiful answer merging one object smoothly into another while animating but I need one object to 'disappear' completely into the other object over time.
"How to transform a moving object into another form in blender" returns searches about copying and duplicating objects.
"How to merge  two moving objects in blender" returns articles on combining objects into a single object, like building a Transformer.


Most reference shape keys and target morphs, but will these work with complex objects? Or simple objects only? 

e.g. Could a white rabbit run across a field and change into a blue duck?

I am new to Blender, so if I'm not asking the right question or using the right terms or if there's a better way to ask this question, I'd be happy to be pointed in the right direction.
Took a while, but found the answer watching an Olav3D Tutorial on Transformation Animations:

Basic Steps:

Add two objects (Object A [Default Cube] and Object B [Suzanne])
Add shrinkwrap modifier to Suzanne, select target--&gt; Default Cube
Apply shrinkwrap modifier as shape key
In Object Data Properties Panel, edit shrinkwrap shape key: Increase shrinkwrap value to 1.0 (this shrinks it down to default cube size)
Click &quot;i&quot; to insert keyframe
Go to frame 100
Decrease shrinkwrap to zero
Click &quot;i&quot; to insert another keyframe
Set up camera and add materials, background, and lighting to taste
Edit render output settings (resolution quality, render samples, etc) to taste
If adding a material to Suzanne, add it to the default cube as well
Change render end frame to 130
Change file format output from PNG to AVI JPEG
Set render output quality to 100%
Render animation and voila! We're done, we successfully transformed(merged/morphed) Object-A into Object-B along the timeline.

Final Result (Better late than never!)