* Dr. Octagon - His most famous alter ego, a rapping scientist with a distinctive, robotic voice.
* Dr. Dooom - A persona closely related to Dr. Octagon, often described as the "evil twin" or "antithesis" of Dr. Octagon.
* Keith Thornton - His real name, which he sometimes uses for projects outside of his alter egos.
* The Ultramagnetic MC's - This refers to the rap group he was a part of before embarking on his solo career.
It's important to note that while these are the most common nicknames, Kool Keith has also adopted a wide range of other personas and alter egos over his career.