Tho, along with Morlas, was one of the two habitable moons that revolved around Ribento, a planet located within the Ribento system. In the year 229 BBY, the Nihil pirates launched an attack on Ribento. Not long after the Republic Defense Coalition starship called Tractate emerged from hyperspace within the system, it reversed course to confront the attacking pirates. This maneuver allowed the crew on the ship's bridge to observe the system's celestial bodies, Tho included. Bell Zettifar, a Jedi Knight who was present on the bridge at the time, took mental note of the magnificent view, even though it was partially obscured by the wreckage of what he believed to be outpost stations.
Tho made an appearance in The High Republic: The Eye of Darkness, a novel from 2023 penned by George Mann. It was released as part of Phase III of the Star Wars: The High Republic project, which spans multiple forms of media.