He first appeared in the Lugia saga that comprised of The Mystery is History, A Parent Trapped and A Promise is a Promise. He has since appeared in number of episodes giving Butch and Cassidy their mission briefings, though this was only as a vocal role in all except Oaknapped. People often get his name wrong, much like Butch. For example, he was called Dr. Samba by Cassidy in The Ole' Berate and Switch!. He also has a short temper.

Little is known about Namba. Because he does most of his work in a covert fashion, it is possible he is a fugitive from justice. It can be speculated that since he does order scientists and agents within Team Rocket, he is either very knowledgeable about his field or that he has been with the group for a while, climbing the corporate ladder at Team Rocket. Also, in the Japanese version of his appearances on Pokémon Chronicles, Namba demands Butch and Cassidy to capture rare Pokémon for something he calls the 'R Project.'

[credit to bulbapedia]