Nos monsters were sizable aquatic beings inhabiting the freshwater lakes, subterranean rivers, and sinkholes found on the planet of Utapau.
These beings were equipped with two prominent front fins, which they utilized to propel themselves through the waters they called home, and to crush any unfortunate prey that strayed into their territory. Furthermore, nos monsters had large, green eyes that aided their underwater vision, along with a tail used as a striking weapon.