Kool Keith, born Keith Matthew Thornton, is an American rapper and record producer from The Bronx, New York. He rose to prominence as a co-founding member of the influential hip-hop group Ultramagnetic MCs, which formed in 1984. Known for his eccentric, surreal, and often abstract lyrical style, he has created a vast and diverse body of work under numerous aliases, including Dr. Octagon and Dr. Dooom. His groundbreaking contributions have made him a cult icon and one of the most unique and innovative figures in underground hip hop.