He's one of the criminal underworld's number one information brokers. He gave information to Kim on Duff Killigan in the episode "Number One" and Dr. Drakken on cybertronic technology in Kim Possible Movie: So the Drama.
Though he can be very serious, "Big Daddy" Brotherson is best known for his childish side, which delights in playing silly games and basically teasing his clients until he is finally ready to make a deal. Anyone who refuses to play along is swiftly and roughly dismissed by his bodyguard.
"Big Daddy" Brotherson first encountered Team Possible at the black market, where they were searching for a lead in Professor Sylvan Green's kidnapping. Global Justice agent Will Du tried to force the information out of Brotherson and was immediately tossed through a window. Kim Possible was able to persuade Brotherson to give up the information with a chocolate bar.
Dr. Drakken approached Brotherson in an attempt to buy information on the cybertronic technology he needed for his latest plot. After several tries, Brotherson finally gave Drakken some very ironic news: that the only genuis to crack the secrets of cybertronics was Dr. James Possible, Drakken's former college friend and Kim's father