Professor Peppler or Professor. Pepura Hakase is the main "antagonist" of Nobita's Secret Gadget Museum ~museum Adventure~. He was the former rival and best friend of Professor Hartman who was banished for almost causing a catastrophic accident at the Gadget Museum's laboratory.
Many years ago, Peppler worked alongside Hartman as a researcher in developing new gadgets. The two got along with each other and Peppler considered Hartman as his dear friend. However, an accident at the research center costed Peppler of his career and he was exiled, leaving Hartman in distraught. Sometimes later, he took Ginger under his wing and raised her while continuing to develop the Peppler Metal as he knew that the Full Metal developed by Hartman will run out one day.
- Peppler is the first "antagonist" to not actually be an antagonist in the movie. He is more of an Anti-Hero.
- His name is possibly based on "pepper".