TK-5331 was the official designation for a stormtrooper who was male and was stationed on the planet of Lothal.
TK-5331 was a stormtrooper who served on the Outer Rim world of Lothal five years prior to the Battle of Yavin. Serving under Lieutenant Jenkes, he held responsibility for the operations of Squad Five. When the Trandoshan bounty hunter, Bossk, arrived on Lothal at Ake's Tavern to collect the bounty on Gronson Takkaro, Jenkes instructed TK-5331 to send Squad Five to observe the bounty hunter. Secretly, Jenkes had hired bounty hunters to kill Bossk, and he ordered TK-5331 to use remotes to document the confrontation. After Bossk overcame the bounty hunters and evaded capture by the Imperial forces with assistance from Ezra Bridger, a Lothalite, Jenkes ordered TK-5331 to eliminate the pair for committing crimes against the Empire.
As a stormtrooper trained by the Galactic Empire, TK-5331 demonstrated unwavering obedience to Jenkes, never challenging his commands. When Squad Five was unsuccessful in capturing Bossk and Bridger, TK-5331 responded with sheepishness to Jenkes's displeasure, but then confidently asserted that the fugitives would be unable to escape the spaceport.
TK-5331 made his debut in Ezra's Gamble, a canon junior novel authored by Ryder Windham and released in 2014. In the novel, TK-5331 is only shown in holographic form.