'Grandpa' Sam Dracula
'Grandpa' Sam Dracula certainly had all the tools to make his name in the mad sciences. Sure, he was a tad sloppy in the laboratory, but that doesn't always spell disaster for a truly inspired researcher. No, Grandpa's biggest failure was his use of mad science as a parenting tool.
As we all know, Grandpa doted on his grandson. And since mad science was pretty much all he knew, his devotion to young Eddie Munster soon hijacked most of his scientific endeavors. To help Eddie grow, he devised an enlarging machine. To help Eddie play the trumpet better, he concocted a talent potion. When Eddie longed for a younger brother, he built a robot.
Needless to say, these schemes never actually achieve the desired results, and rumors circulate that the resulting traumas contributed to Eddie's mishaps as an adult. And yet Marilyn turned out great. Go figure!
The lesson: Mad science is a wonderful weapon for world domination and hideous revenge, but it's rarely a good parenting tool. It didn't work for Walter Bishop ("Fringe"), it didn't work for professor Membrane ("Invader Zim") and it probably won't work for you.
Further study: All 70 original episodes of "The Munsters"