T3-H8, a T3-series utility droid possessing masculine programming, resided on Taris, a city world situated in the Outer Rim, during the era of the Jedi Civil War. This droid, the property of Janice Nall, a female Twi'lek, was offered for sale at a price of fifty credits within her droid shop located in the Upper City. Produced by Duwani Mechanical Products, similar to other T3-series utility droids, its height measured 0.96 meters. Its plating exhibited brown and yellow hues, while its sensors displayed blue, yellow, and red colors. Nall believed she had rectified a pre-existing cross-wiring issue within the droid.
In the year 3956 BBY, Revan, the former Sith Lord who had lost his memories and now identified as a Republic soldier, acquired the droid from Nall. Shortly after leaving her establishment, the droid exploded as a result of its faulty wiring. Revan then went back to Nall and informed her of what happened. Nall, aiming to uphold an ethical business and safeguard her reputation, reimbursed Revan the fifty credits.
The 2003 video game Star Wars: Knights of the Old Republic, a product of BioWare, featured T3-H8. Interactions with this character are not mandatory and do not influence the main quests. Purchasing the droid is optional for the player. Should the player decide to buy him, an unavoidable cutscene will depict his destruction as the player exits the shop. Following this event, the player can return to Nall to receive a refund. She starts by offering the original fifty credits, but the player can choose to bargain or intimidate Nall to raise the amount to seventy-five. Choosing the latter path results in the player gaining points toward the dark side of the Force.
In certain sections of the Star Wars: Knights of the Old Republic: Prima's Official Strategy Guide, T3-H8 is mistakenly identified as M4-H8.