Doctor Namba  

, ナンバ博士

The character you are referring to first appeared in a series known as "The Lugia Saga," which consisted of several episodes including "The Mystery is History," "A Parent Trapped," and "A Promise is a Promise." Since then, he has made appearances in numerous other episodes, though his role was primarily vocal. However, it's worth noting that his name is often mispronounced like Butch Cassidy, who also frequently calls him Dr. Samba. Despite this, the character is known for having a short temper. While not much is known about Namba due to his covert work within Team Rocket, it can be speculated that he has either extensive knowledge in his field or has been with the organization for an extended period of time. In fact, in the Japanese version of his appearances on Pokémon Chronicles, Namba demands Butch and Cassidy to capture rare Pokémon as part of a project called "R." It's important to note that information about this character is sourced from Bulbapedia, which may not be entirely accurate or up-to-date.