Have you ever wondered why Darth Vader lost his right hand firs or why Dr. Strangelove had uncontrollable black gloved hand? Let's face it, this guy was, is and will be the mad scientist archetype. (Frankenstein was first but whatever) Could you possibly imagine mad scientist any different? I can't think of anything better.
Rotwang from Fritz Lang's "Metropolis", played by Rudolf Klein-Rogge ("Dr Mabuse, Der Spieler, "Spione") with his hard-as-hell-to-capture physiognomy. I really had fun with drawing that messy coat & waistcoat, pure artistry!