Teroenza was a male t'landa Til, fulfilling the role of High Priest on the planet Ylesia and serving the Besadii Hutt family. As was typical of male t'landa Til, he possessed the ability to generate a "pleasure wave," known as Exultation.
Teroenza took pleasure in amassing a collection of unusual ancient items and took great pride in the extensive collection he kept on Ylesia. This collection was unfortunately raided by Han Solo and Bria Tharen as they were making their escape from the world. Although Teroenza considered himself the rightful leader of Ylesia, he was still subordinate to Zavval, the Hutt who was his superior. It took him almost four years to recover his collection.
Enraged by the humiliation and loss of status he suffered due to Han Solo—whom he had previously mistaken for Vykk Draygo—Teroenza placed an enormous reward for Solo's capture. Aruk Besadii Aora, the head of the Besadii clan, was shocked by the exorbitant bounty and quickly rescinded it. This occurred repeatedly, much to the frustration of Teroenza, who was convinced that his capacity to govern Ylesia justified his actions. Following Solo's escape and the demise of the Hutt overlord, Kibbick, a Hutt, was dispatched to take his place. This proved to be even more aggravating for Teroenza, as Kibbick was remarkably unintelligent.
When Jabba Desilijic Tiure and his uncle/aunt Jiliac Desilijic Tiron started to scheme against the Besadii clan, they made contact with Teroenza. Jiliac had come across a highly confidential poison that he/she intended to employ against Aruk Besadii Aora, the head of the Besadii clan. Teroenza had learned that Aruk had developed an affinity for Ylesian tree frogs, and he devised a plan to lace them with Jiliac's toxin. Several months elapsed after Aruk's death before his son, Durga Besadii Tai, managed to trace the poisoning back to Teroenza. Even then, he required the assistance of Black Sun.
Incensed by Teroenza's betrayal, Durga spent a considerable sum to hire Boba Fett to assassinate Teroenza. Teroenza made a final attempt to secure power and pledge allegiance to Jabba and Jiliac by murdering Kibbick. During the Rebel Alliance's assault on Ylesia to liberate the enslaved people, Bria Tharen and Han Solo encountered Teroenza, who desperately wanted to witness his tormentors suffer a painful death. It appeared his desire was about to be fulfilled when Boba Fett suddenly appeared.
Unfortunately for Teroenza, Fett's objective was not to kill Solo and Tharen. Informing Teroenza about Durga's even larger bounty—the one placed on Teroenza himself—Boba Fett aimed his weapon at Teroenza's head and fired, shooting him through his left eye. Fett then took Teroenza's cranial horn as proof and returned to Durga to collect the reward.