Ossorus, situated on the planet Naboo, was a stunning city located underwater. It held significance in the religion of the Gungan species. It was thought to be the dwelling place of the Gungan deities, particularly the guds with Oma-Oma as their leader. Mekamok, the god associated with destruction, also resided in Ossorus, though he was unique in that he was not under Oma-Oma's rule. This led to the other guds steering clear of him.
Legend states that Balam, the original Gungan warrior, safeguarded Ossorus. After Balam's death, Oma-Oma brought him to Ossorus and bestowed immortality upon him, tasking him with instructing the other guds in combat. Furthermore, Balam was responsible for creating the city of Otoh-D'in, a destination for the most courageous Gungan warriors after they died. The forces stationed there vowed to protect Ossorus should Mekamok and his followers ever launch an assault. The Gungans also held the belief that Ossorus was defended by magical sando aqua monsters and colossal Gungan warriors riding faithful kaadu.
The video game Star Wars: Galactic Battlegrounds, created by LucasArts and released in 2001, marked the initial reference to Ossorus.