Tholothians were a humanoid sentient species. Largely similar to humans in appearance, their primary distinguishing characteristics were their scaled craniums, with skullcaps that sprouted fleshy head-tendrils, and partially bluish skin pigmentation, particularly around the eyes. The Tholothians’ skullcaps could be white, red, or blue in color. Some Tholothians, such as D’urban Wen-Hurd, instead possessed hair on their heads. Male Tholothians could grow facial hair. Their skin could be brown or pale. It was possible for Tholothians to be Force-sensitive.

The Tholothian government, which governed the species’ homeworld of Tholoth, was a democracy with an executive branch and a senate of legislators. The government banished heavy industry to other planets in the Tholoth system to preserve the natural environment of Tholoth. The government also instituted policies to limit the flow of offworld visitors, and insisted that newcomers integrate in ways that minded Tholoth’s ecology. Tholothian cities incorporated foreign architectural designs with distinct Tholothian twists.

Traditional Tholoth headdresses were worn by many Tholothians as part of their culture. The headdresses consisted of brown fabric bands which went around the head and covered the ears, connected to a web of delicate chains which traced the scales of the wearer’s scalp.