The core humor of the "Mr. and Mrs. Mad Scientist" idea was the conflict between the divine and the mundane, the intellectual and the practical. Mr. Mad Scientist would always be seeing things in the big picture: When confronted with breakfast, he would describe each thing on his plate in scientific detail, or marvel at the ability of the earth to provide food, and his wife would say, in a kind tone, "Eat your toast, dear."
I thought it could be a little bit "Addams Family," with some bizarre family habits like having a brain in a jar for a pet. I envisioned three panels like the one above, with the grandson holding a leash attached to the jar, and in the fourth one he'd say, "I wish grandpa would get us a real pet."
I thought it could be a bit "Jim's Journal," a cartoon that made a point of abandoning the "setup - beat - gag" formula of modern comic strips. Actually, rethinking the above gag, the punchline would be in the third panel, and in the fourth he'd still be standing there.
And I thought it could be a little bit "Calvin and Hobbes," where the scientist and his granddaughter could banter about the nature of the universe and social problems, where I could say some outrageous things in the context of this "mad" family.
Of course I never got far enough along to create this world ... I'm surprised I even got that far before I remembered that I have other writing projects much more important to me!