If you ever wanted to see how a Mighty Max playset was created from the ground up back in the 90’s, The Construction of Dr. Zygote thread (registration required) on the Mighty Max Archives is the place to see it. It’s truly magical seeing one of the original toy line designers making a brand new addition to the line from scratch, and all for the benefit of Mighty Max fans.
EDIT 6/21/18: The forum moved and is virtually dead, and I can’t find the thread anymore, so I uploaded all the sketches I salvaged from it.
Mike's Toybox 