Fan Casting Bungling Inventor in Sort by Tropes

A trope that started out as a subversion of the Gadgeteer Genius, but is now a trope in its own right, the Bungling Inventor is a scientist (often a Mad Scientist) whose inventions never seem to work properly. In fact, they're prone to truly spectacular cases of Phlebotinum Breakdown. The inventions might do something entirely different than what they were supposed to (like explode, or play "Yankee Doodle Dandy"), or they might seem to do their primary function but have some subtle flaw, or they might work a little too well (like a security robot that throws everyone out of a house, including the people it was designed to protect).