TK-422 was the identifier for a stormtrooper assigned to Death Star I during the time of the Galactic Civil War. Following the capture of the Millennium Falcon, he received orders to maintain a post guarding the entrance to the freighter's boarding ramp, while a group of scanners tried to ascertain whether anyone was concealed on the Falcon.
Mere moments after the scanning team had proceeded onto the boarding ramp, a distinct thud resonated, and a voice called down, requesting assistance from TK-422 and his fellow guard, TK-421, with a piece of equipment. The two stormtroopers ascended the ramp to provide aid to the now-unconscious technicians. Instead, TK-422, together with TK-421, was stunned by Han Solo, divested of his armor, bound, and confined within one of the Falcon's utility lockers. Solo then put on his armor, expressing distaste for the odor and suggesting that TK-422 had poor hygiene habits. Luke Skywalker appropriated his weapon.
When a gunfight erupted between the personnel of Detention Block AA-23 and a Wookiee accompanied by two stormtroopers, a security detail was sent to the hangar where the recently seized freighter was located. TK-422 and his unresponsive companions were discovered on the Falcon. After failed attempts to rouse him, TK-422's fellow stormtroopers transported him to the closest medical facility.
In Star Wars (1977) 3 this character is shown as being a member of Scanning crew BT-445.