The Tolos, along with the Lomins were one of the two sentient species originally from the Panto system found in the Core Worlds. These beings evolved on the planet called Toloran, and they collaborated with the amphibious Lomins from Pantolomin, the first planet in the system's, to establish a tourist destination spanning the entire system. The Tolos offered a variety of winter-themed recreational activities on their homeworld.
In the Core Worlds' Dolomar sector, the Panto system was home to the sentient species known as the Tolos, who originated on Toloran, the second planet of that system. Their homeworld was a frigid, mountainous, and snowy world, which they shared with non-sentient ice dragons. The Tolos joined forces with another intelligent species of the star system, the amphibious Lomins from Pantolomin. Together, these two species transformed the entire system into a large tourist resort for beings across the galaxy.
The Tolos' homeworld featured a wide array of winter activities, such as repulsor skiing, hover sledding, and wilderness survival camps. Tourists could also journey on the Snow Nara ice barge through icy waters, or embark on hunting expeditions in search of ice dragons. These pastimes complemented the underwater tours and casinos offered on Pantolomin, as well as the zero-gravity activities available on Atloran, the system's third planet. The Tolos and the Lomins shared representation on the system's tourism board.
Bill Slavicsek created the Tolos for the Dark Force Rising Sourcebook, a roleplaying game supplement published by West End Games in 1993. This information was later reprinted in The Thrawn Trilogy Sourcebook in 1996. Despite an additional mention within the Pantolomin article of issue 124 from The Official Star Wars Fact File, Slavicsek never gave a description of the Tolos, and they still lack an official depiction.