Kaanuub was a Valusian nobleman and the baron of Blaal. As a member of the old ruling dynasty of Valusia with a legitimate claim to the throne, and an ally of the Serpent-Men, he constantly plotted to overthrow Kull. Kaanuub conspired with the wizard Tuzun Thune in a failed attempt to destroy Kull by imprisoning the king's soul in Tuzun's magical mirrors.
He was later involved in another failed plot to depose Kull with the help of other conspirators led by the outlaw Ascalante (not to be confused with Ascalante, the Conan character). The other conspirators included Gromel, Ridondo, and Volmana. Ascalante regarded Kaanuub as a fool and a coward, but the baron's great wealth was essential to Ascalante's plans. Although it was Kaanuub who first requested Ascalante's help in the matter, the outlaw intended to get rid of Kaanuub and take the crown for himself if their plan had been successful.
Kaanuub is described as short and fat, with a timid nature despite all his intrigues and scheming. He did not participate in the direct attack by his compatriots against Kull in his royal bedchamber. Kaanuub's extreme nervousness threatened the success of the plot so he had been told to remain at home until the deed was done. It is remarkable that Kaanuub apparently avoided punishment long enough to be involved in more than one attempt on Kull's life, and his ultimate fate is unclear.