The zeldrate was a predatory reptilian species that inhabited the verdant plains of Balmorra. Its primary food source was the large grazing animals called bormu, which it targeted when they strayed from the safety of their groups. In contrast to the numerous herbivorous bormu, the zeldrate population was small due to Balmorran industries that harvested the reptiles for a corrosive chemical secretion. This secretion was used as a cleaning agent for various industrial components.
During the Cold War, Imperial forces subjected Balmorra's surface to heavy bombardment, which resulted in the destruction of its industrial facilities. As a result, the bormu population declined due to field contamination, while the zeldrate population increased because the industries were operating at less than half capacity. These changes led to zeldrates consuming fewer bormu, which compelled the predators to seek alternative prey. They began to hunt sentient beings, including Imperial soldiers and resistance fighters, primarily targeting those injured in combat. Contemporaneously, a zeldrate population also existed on the plains of Dantooine.