The tach represented a species of primates that were native to the planet of Kashyyyk, residing in trees and lacking sentience. These creatures, known for their harmless and affable nature, were frequently observed foraging for overly ripe fruits on the ground. They possessed distinctive features, including vibrant, reddish skin, fur that was white on their heads and a grayish-blue hue on the rest of their bodies, and a lengthy tail adorned with a tassel-like end. Their mode of locomotion involved walking on all fours, with arms that surpassed their legs in length. During Cal Kestis' mission to Kashyyyk in 14 BBY, he encountered a number of tachs inhabiting the Origin Tree as he ascended it. Subsequently, his droid companion, BD-1, performed a scan of these creatures, providing Cal with data pertaining to them.
The initial appearance of tachs within the present Star Wars canon occurred in the 2017 video game titled Star Wars Battlefront II. The tach has its roots in the Star Wars Legends timeline, making its debut in the 2003 video game Star Wars: Knights of the Old Republic.