Kool Keith

In 2018, Keith collaborated once again with Dan the Automator and DJ Qbert for another Dr. Octagon album. Moosebumps: An Exploration Into Modern Day Horripilation was released on streaming services on April 6, 2018, with the physical release scheduled for Record Store Day, April 21, 2018. The Record Store Day release includes both vinyl and CD copies. Using his Deltron persona, Del the Funky Homosapien guests on "3030 Meets the Doc, Pt. 1". NPR offered a first look at the album on March 29, 2018. Kool Keith appears on "Western" by the bluegrass-rap group Gangstagrass, performing as himself.

In 2007, Ultramagnetic MCs released the reunion album The Best Kept Secret. In 2009, Kool Keith released the concept album Tashan Dorrsett; a follow-up, The Legend of Tashan Dorrsett, followed two years later. In 2012, Kool Keith performed at the Gathering of the Juggalos. He has stated that he is considering retiring from music. In 2013, Keith appeared as Dr. Octagon on the Yeah Yeah Yeahs song "Buried Alive", from their album Mosquito. In 2015, Keith released "Time? Astonishing!" with producer L'Orange and began the start of his relationship with Mello Music Group. Since then, Keith also re-issued his group album with the Analog Brothers (Ice-T, Pimp Rex, Marc Live, Silver Synth) "Pimp To Eat" with Mello Music. Kool Keith's recent solo album Feature Magnetic was dropped on September 16, 2016 and it features MF DOOM, Slug from Atmosphere, Dirt Nasty and many others. Artwork for the "Feature Magnetic" album was produced by Marc Santo.

Thornton's lyrics are often abstract, surreal, and filled with non-sequiturs and profane humor. Thornton is also known for an explicit style focusing on sexual themes, which Thornton has referred to as "pornocore". In a 2007 interview, Thornton claims to have "invented horrorcore".

On April 25, 2006, Thornton released the album Nogatco Rd. under the name Mr. Nogatco.

On October 12, 2004, Real Talk Entertainment issued the album Dr. Octagon Part 2. The album was discontinued by court order. On June 27, The Return of Dr. Octagon was released by OCD International, an imprint of CMH, advertised as the official follow-up to Dr. Octagonecologyst. Some critics felt that it was not as good as its predecessor. Thornton stated that he liked the album, but felt that it hurt his reputation as a musician. In August, Thornton performed under the Dr. Octagon billing, but did not acknowledge the release of the OCD album.

In 2002, Thornton began recording The Resurrection of Dr. Octagon with producer Fanatik J, signing a contract with CMH Records to release the album, which was eventually completed without much input from Thornton, due to a falling out over contractual terms.

Thornton, Marc Live and H-Bomb formed the group KHM, releasing the album Game on November 19, 2002, changing their name to "Clayborne Family" by the release of their second album.

On June 5, 2001, Thornton released the album Spankmaster on Gothom Records. It peaked at #16 on the Billboard Heatseekers chart, #11 on the Top Independent Albums chart and #48 on the Top R&B/Hip-Hop Albums chart.

On July 25, 2000, Thornton released the album Matthew. It peaked at #47 on the Billboard Heatseekers chart. The same year, Thornton collaborated with Ice-T, Marc Live, Black Silver and Pimp Rex for the album Pimp to Eat, under the group name Analog Brothers, with Keith performing as Keith Korg and Ice-T as Ice Oscillator.

In 1996, Thornton collaborated with Tim Dog for the single "The Industry is Wack", performing under the name Ultra—the album Big Time soon followed. In 1999, he released the album First Come, First Served under the name "Dr. Dooom", in which the album's main character killed off Dr. Octagon on the album's opening track. The same year, on August 10, 1999, Thornton released Black Elvis/Lost in Space. It peaked at #10 on the Billboard Heatseekers chart, #74 on the Top R&B/Hip-Hop Albums chart, and #180 on the Billboard 200, and stands as Thornton's most commercially successful project to date.

Thornton followed the Dr. Octagonecologyst album with Sex Style in 1997, under the name Kool Keith.

Thornton released his first notable solo single, "Earth People", in 1995, under the name Dr. Octagon. This was followed by the release of Dr. Octagonecologyst the following year. The album's production by Dan the Automator and Kutmasta Kurt, with scratching by DJ Qbert was acclaimed by critics, and the album was released nationally by DreamWorks Records in 1997, after an initial release on the smaller Bulk Recordings label (as, simply, Dr. Octagon) a year prior. DreamWorks also issued an instrumental version of the album, titled Instrumentalyst (Octagon Beats).

After continuing with Ultramagnetic for two more albums (1992's Funk Your Head Up and 1993's The Four Horsemen), Thornton would embark on a solo career.

Kool Keith was a cofounding member of Ultramagnetic MCs, whose debut Critical Beatdown was released in 1988. After two more albums with the group, Funk Your Head Up and The Four Horsemen, Kool Keith released his critically acclaimed solo debut album, Dr. Octagonecologyst under the name Dr. Octagon in 1996. He subsequently released a series of further independently released hip hop albums, including Sex Style, First Come, First Served (as Dr. Dooom), and most recently Keith.

Kool Keith began his career with the group Ultramagnetic MCs. After the release of their influential 1988 album Critical Beatdown, Thornton was reportedly institutionalized in Bellevue Hospital Center. However, he later said that the idea that he was institutionalized came from a flippant remark made during an interview, and he never expected the story to become so well known.

Keith Matthew Thornton (born October 7, 1963), better known by his stage name Kool Keith, is an American rapper and record producer from The Bronx, New York known for his surreal, abstract and often profane or incomprehensible lyrics. Kool Keith has recorded prolifically both as a solo artist and in group collaborations. Kool Keith is generally considered to be one of hip-hop's most eccentric and unusual personalities.