Zargotians have yellow-colored skin and black eyeballs. Small radial indentations extend around a bald scalp. They were technologically advanced and had built at least one interplanetary spacecraft.
In the 2260s, Zargotians contracted a deadly plague they referred to as a creeping sickness. As more and more people became hospitalized and monitored in biobeds, leading physician Doctor Ixta studied the disease. The epidemic worsened to the point that Zargotians were crashing groundcars and lying prostate in the street.
In 2266, a Zargotian cruiser was dispatched to Coltac to retrieve herb samples that might lead to a cure. A problem with the ship's stabilizers triggered an explosion just as it was spotted by the Federation starship USS Enterprise. Doctor Leonard McCoy and Brad tried to help a dying Zargotian they recovered from an escape pod. Before he died, he begged them to help his people.
McCoy and Captain James T. Kirk beamed down to the planet's largest city and met with Ixta. The Enterprise retrieved Coltac herbs, and within a short time the entire population was inoculated and cured. Zargotians celebrated with fireworks. (TOS comic: "Target: Zargot")