Large Professor

William Paul Mitchell (born March 21, 1972), better known by the stage name of Large Professor (also Extra P. and Large Pro), is an American rapper and music producer. Based in New York City, he is known as a founding member of the underground hip hop group Main Source and as a mentor and frequent collaborator of Nas. About.com ranked Large Professor at No. 13 on its Top 25 Hip-Hop Producers list.