The Clone Master first appears in Brown's 1980 adventure Assault on the Clone Master, described as a "nebbish-looking man with horn-rimmed glasses" who lives in a fortress in another universe and holds power by using his Clonatorium to create endless armies of guards. With the help of some local rebels, the adventurer invades the fortress, destroys the Clonatorium, and kills the Clone Master. A similar version of the character appears in Keith Dechant's 2017 remake which is set on Eamon in the land of Knieriem.
Frank Black's Fiends of Eamon reveals that the Clone Master survived the assault on his fortress in Brown's original story and followed the adventurer back to the world of Eamon, there setting up a new lab and Clonatorium on a distant, storm-shrouded island. The guild directs the adventurer to destroy his operation and kill the Clone Master once and for all.