The Goa'uld (pronounced "Go-ah-oold" or sometimes "Goold") are an aquatic species of symbiotes from the planet P3X-888 in the Milky Way galaxy. The Goa'uld took over beings as hosts, taking complete control of their bodies. Most are known to be extremely egomaniacal due to their genetic memory, and were capable of living thousands of years.

The Goa'uld first arose in the waters of P3X-888, originally as predators. Eventually, they began taking the native Unas as hosts, becoming more adaptive. They eventually learned how to operate the Stargate the Ancients placed on P3X-888 and left, taking Unas slave armies with them. (SG1: "The First Ones")