Kassek-Ka was the chieftain of a male Codru-Ji clan. In the year 137 ABY, Darth Kruhl reached out to another clan leader, Rikkar-Du, proposing that if he pledged allegiance to the Empire under Darth Krayt, he would be granted authority over all the clans of Munto Codru. Kassek-Ka was present at a gathering of clan leaders where Rikkar-Du attempted to persuade the others to unite against Imperial rule. Kassek-Ka voiced his opposition to the idea of a unified alliance, arguing that it deviated from their traditional practices of scheming, abductions, and power grabs.
Following the meeting's conclusion, Rikkar-Du met with his wife, Tassa, instructing her to return to their tent with their son, Jassar. Sometime after Rikkar-Du departed for the temple and Jassar wandered away from his mother, Kassek-Ka killed Tassa. Darth Kruhl confronted Rikkar-Du about revealing his proposition. When Jassar intervened to defend his father, Khrul slew him before assassinating Rikkar-Du, an act prearranged between Khrul and Kassek-Ka as a warning against defying the Sith. Subsequently, Kassek-Ka affirmed his acceptance of Darth Khrul's offer and his willingness to adapt to the changed circumstances.
Kassek-Ka made an appearance in Legacy (2006) 13. The lettering style of the comic, which used all capital letters, makes it uncertain whether the third "k" in his name should be capitalized. However, the 2008 reference book, The Complete Star Wars Encyclopedia, writes it as uppercase, where the character is mentioned in Tassa's entry.