Origin
Mr. Big is the alias of Dr. Kananga. He is a restaurant owner of a chain of restaurants in new York City and New Orleans called Fillet of Soul while simultaneously running his drug empire. He eventually gets the attention of MI6 and James Bond.
Creation
Mr. Big was created by Ian Fleming for the novel Live and Let Die.
Other Media
In the 1973 film Live and Let Die, Mr. Big is played by Yaphet Kotto.