The seas of Tarnoonga were the homes of giant sea monsters such as the Miridon, who made its nest in the ruins of sunken freighter ships settled atop the undersea mountain ranges. The peaks of many of these mountains stretched upward, breaking the ocean's surface, forming immense natural caverns and grottos.
Some years prior to the Battle of Yavin, the pirate known as Gir Kybo Ren-Cha established a hideaway base inside the depths of one of these tall mountain peaks. His crew horded the purloined treasures from nearby worlds such as Tammuz-an and hid them within private caches inside the mountain tops. Kybo kidnapped Jann Tosh and Jessica Meade, heroes affiliated with Tammuz-an, and brought them to his grotto on Tarnoonga. With the help of the droid team of C-3PO and R2-D2, however, Tosh and Meade were able to escape.
- Star Wars: Droids—"The Pirates of Tarnoonga" (First appearance)
- The Pirates of Tarnoonga: A Droid Adventure
- A New Hope: The Life of Luke Skywalker