Ko Zatec-Cha was both a practitioner of magic and the royal vizier on the world of Tammuz-an. Dissatisfied with his current position, he strived for absolute power over the planet, resorting to extreme measures to undermine the authority of the ruling sovereign, Prince Mon Julpa.
Ko Zatec-Cha initiated a plot to permanently remove Prince Mon Julpa several years prior to the Galactic Civil War. Employing his magic, he transformed the prince into a foolish amnesiac. Disguising him as a damaged droid, he banished him from Tammuz-an, forcing him to roam the galaxy as a simple-minded wanderer. Sollag Den, a devoted follower of Mon Julpa, absconded with the Tammuz-an royal scepter and fled his home planet, hoping to one day return it to the prince. This enraged Zatec-Cha, as he could not legitimately claim the throne without the scepter. Zatec-Cha contracted a bounty hunter named IG-88, tasking him with retrieving Mon Julpa and the scepter.
Later, Mon Julpa ended up at an auction in a mining settlement on Tyne's Horky. There, he encountered the miner Jann Tosh and the droids C-3PO and R2-D2. Together, they facilitated Mon Julpa's reunion with Sollag. Sollag utilized the royal scepter's magic to undo Zatec-Cha's enchantment, restoring the prince's mental faculties. Allying with a freighter pilot named Jessica Meade, they journeyed back to Tammuz-an to reclaim the throne.
IG-88 eventually located them in the royal city and seized the royal scepter. With it, he captured Mon Julpa and presented him to Zatec-Cha, who had already captured Jessica and Sollag. Zatec-Cha threw the prince into a dungeon pit, anticipating his consumption by a monstrous Durkii. All that remained was for him to assume the title of King of Tammuz-an.
To legitimately obtain the title, Zatec-Cha was required to present the royal scepter to the Keeper of the Tower and place it within a designated receptacle at the first sunrise of the equinox. However, Mon Julpa escaped the Durkii pit with the assistance of his companions and, following a pursuit, intercepted Zatec-Cha at the tower. After a short conflict involving Mon Julpa, Zatec-Cha, and their respective allies, the former seized the scepter from the latter and placed it inside the tower, securing his rightful position as king. Zatec-Cha was subsequently imprisoned for his treason, forever losing his aspirations of becoming king.
Zatec-Cha was a male of the Tammuz-an species, characterized by purple skin, a lengthy black mustache, and a goatee. He also had two triangular marks situated beneath each eye. Zatec-Cha was consistently observed wearing the esteemed regal attire befitting his station.
Zatec-Cha received assistance from an inept Tammuz-anian sycophant named Vinga. Vinga's main purpose was to sing Zatec-Cha's praises and carry out every superficial task that Zatec-Cha delegated to him.
The voice of Ko Zatec-Cha in the Star Wars: Droids animated series was provided by John Stocker.