Clubber Lang is fictional.
James `` Clubber '' Lang is a fictional character created by Sylvester Stallone for the film Rocky III , which was released in 1982 . Lang serves as the main antagonist of the film and was portrayed by Mr. T. Lang is a professional boxer fighting out of Chicago , Illinois and a one-time world heavyweight champion , having taken the title from Rocky Balboa only to lose it back to Balboa in his next fight . The character is very loosely based on a combination of Sonny Liston , Larry Holmes and George Foreman .