Tiaan Jerjerrod existed as a human male who functioned as both a bureaucrat and a military officer. He achieved the ranks of Rear Admiral and Moff while serving the Galactic Empire during the Galactic Civil War. The Empire itself was the successor state to the Galactic Republic. Jerjerrod's initial occupations included being an architect and a designer of starships, but he eventually ascended to the position of Moff. He received the assignment of station commander for the DS-2 Death Star II Mobile Battle Station, a decision influenced by his prior involvement in the construction of the first Death Star.
Jerjerrod's responsibility was to manage the challenging final construction phase of the battle station. This task put him in a precarious position, incurring the displeasure of both the Sith Lord Darth Vader and his superior, Emperor Sheev Palpatine, due to construction delays. Vader cautioned Jerjerrod that the Emperor would not accept further delays, but when the Emperor visited the Death Star, he mostly disregarded Jerjerrod. However, the Emperor did authorize Jerjerrod to utilize the station's superlaser against the Rebel fleet's starships during the Alliance to Restore the Republic's attack on the Death Star. This battle resulted in the station's destruction and the death of everyone aboard, including Jerjerrod.

Hailing from the Core World of Tinnel IV, Tiaan Jerjerrod, a human male, was born there in 35 BBY. He came from a prosperous family. He later attended the University of Coruscant, where he participated in the Taung & Zhell Society. During his younger years, he was a dedicated engineering student, and his excellent academic performance led to a position drafting warehouse designs. His plans for a freight depot located on Ord Mantell caught the attention of the Corellian Engineering Corporation, which resulted in his employment as a starship designer. His designs for an interstellar trash hauler eventually led to his recruitment by the Galactic Empire.
Jerjerrod excelled within the structured environment of the Imperial Navy. By 14 BBY, he had achieved the rank of Rear Admiral and was a member of the Joint Chiefs. He contributed to the construction of the first Death Star, a moon-sized battle station that utilized kyber crystals to generate a planet-destroying superlaser. Jerjerrod convinced himself that the mere existence of such a weapon would serve as a deterrent, providing defense for the Empire without requiring its use. However, the Empire did employ the megaweapon, resulting in the blowing up of Alderaan. Despite its immense power, the station was ultimately destroyed when Luke Skywalker of the Alliance to Restore the Republic, launched two proton torpedoes into a vulnerable thermal exhaust port. The torpedoes triggered a chain reaction within the reactor core, leading to its explosive demise.

Not long after the Battle of Hoth, and following Darth Vader's unsuccessful attempt to sway his son, Luke Skywalker, to the dark side of the Force during their confrontation on Cloud City, Vader returned to his personal flagship, the Executor. Jerjerrod was among the officers present in the hangar bay to receive the Sith Lord.
Jerjerrod eventually attained the rank of Imperial Moff. Despite the failure of the initial superweapon, the Emperor mandated the construction of a second Death Star above the forest moon of Endor. Jerjerrod was appointed as the station Commander and tasked with overseeing the challenging project of completing the superweapon. He was given the cover title of Director of Imperial Energy Systems due to the project's need for secrecy. To accomplish this difficult task, Jerjerrod worked tirelessly, dedicating himself to the plans and extensive paperwork. He notably ensured that all exhaust ports on the new station were heavily armored, correcting a critical flaw in the original Death Star's design. However, the architect faced numerous obstacles, including budget reductions, supply chain disruptions, and a shortage of construction personnel.

The evident lack of progress on the Death Star eventually prompted Vader, the personal enforcer of Emperor Palpatine, to visit the station and address the situation. Upon learning of Vader's transport's arrival in one of the station's hangar bays, Jerjerrod went to the hangar to greet the Emperor's representative as he exited his shuttle. Feeling confident in his position, Jerjerrod intended to present Vader with detailed daily reports, hoping to gain his support and demonstrate the impossibility of the Emperor's demands. However, Vader dismissed Jerjerrod's formal greeting and directly stated the purpose of his visit: the Emperor was dissatisfied with the slow pace of the Death Star's construction, and Vader was there to ensure its timely completion. Jerjerrod initially protested that the project was understaffed and nearly impossible under the current conditions. However, when the Sith Lord announced that the Emperor would personally oversee the final stage of the station's completion, Jerjerrod pledged renewed dedication from himself and his crew. He acknowledged Vader's warning that the Emperor would not tolerate failure and that the Dark Lord of the Sith was less forgiving than his apprentice.
Following Lord Vader's threat, Jerjerrod went back to his personal quarters before coming up with a plan. Using the schematics to locate Vader's meditation chamber, he waited for the Sith Lord there and offered to take him on a tour of the battle station, hoping his imposing presence would provide motivation for the workers. Together they traversed the massive station, taking shuttles and lifts to travel as necessary. Vader told Jerjerrod that he saw adequate work and asked what the Moff thought was causing the delays. Having already said that the timeline was the real issue, Jerjerrod guessed that Vader was referring to one of the biggest design changes: the new venting system that would prevent the station from being exploited as the first iteration had. However, Vader was displeased by the answer and told Jerjerrod to not focus on past failures before striding off.
Returning to his quarters, Jerjerrod once again contemplated the impossible situation he was in. He simply did not have enough time or resources to get the massive battle station operable. Then, he considered what operable could mean. He decided to focus the majority of the labor on finishing the superlaser, which was designed to be the last part of the station completed. When he presented this idea to Vader, he simply replied that Jerjerrod must remember that any work worth doing was worth doing well before departing.
Driven by the fear of the Emperor's arrival, the Moff exhausted himself and his workers for several weeks. In spite of his best effort, the Moff was unable to finish the station before Palpatine's arrival, and one whole hemisphere was still covered in scaffolding and girders. When Palpatine finally arrived aboard the Death Star with great fanfare, Jerjerrod joined Vader and a group of Imperial officers to welcome their ruler and his retinue. The Moff had hoped that he would be rewarded for his hard work, but, despite Vader's earlier warnings, the Emperor ignored Jerjerrod and the other officers as he conversed with Vader about their grand plan to destroy the Rebel Alliance, with which the Empire had been at war for four years. Jerjerrod soon realized that not having displeased his master was enough of a reward.
Inside of the Emperor's throne room, located on a spire high above the surface of the Death Star, Jerjerrod and the Emperor's advisors, Sim Aloo and Janus Greejatus, looked on as the Emperor tasked Vader with setting the trap for the rebel fleet at Endor. After ordering his apprentice to return to his command ship, Vader and Jejerrod exited the throne room.

The Rebel Alliance unknowingly took the Emperor's bait, launching a two-pronged, all-out assault on the Death Star's construction site at Endor, in which a strike team infiltrated onto the forest moon's surface would disable the deflector shield protecting the space station while Rebel starfighters, supported by the capital ships of the Alliance fleet, would fly into the Death Star's superstructure and take out its reactor, thereby destroying the weapon before it could be completed. When Vader learned of the strike team making to the planet and that his son, Luke Skywalker was with them, he attempted to return to the throne room to inform Palpatine, not knowing that the Emperor decreed he wasn't to be disturbed by anyone. When Vader arrived at the entrance of the turbolift, he was stopped by Jerjerrod and two of the Emperor's Royal Guards. Jerjerrod informed Vader that he wasn't to enter, but Vader simply began choking him with the Force. In-between choking for air, he managed to say that it was the Emperor's command, prompting Vader to release him and state he would await Palpatine's convenience.

Once the Rebel fleet arrived and found itself trapped between the Imperial Navy, having hidden itself on the far side of Endor, and a still shielded Death Star, as Palpatine had anticipated them and tasked an entire legion to capture them before they could destroy the shield generator, he contacted Jerjerrod on the station's Overbridge and authorized him to target and destroy the Rebel starships with the Death Star's superlaser. Under his command, the Death Star atomized the Liberty and the Nautilian as the battle progressed. The Imperials were forced to stop firing the superlaser, however, when the Rebels fought the Imperial Navy at point-blank range to prevent the Death Star from being able to destroy their ships without destroying any of their own. When the Rebels on the planet were aided by a native Ewok tribe, they were able to destroy the Death Star shield generator, and as a result, the Alliance soon gained the upper hand. The battle concluded with the Emperor's death and the destruction of the Death Star with all hands lost, Jerjerrod included.
While Tiaan perished over Endor, his descendants joined the First Order, the Imperial successor regime to the fallen Galactic Empire. His grandson, Jothan Tiaan Jerjerrod, the son of First Order officers Jax Jerjerrod and Jul Jerjerrod, defected from the First Order and joined the Resistance.

In contrast to the majority of officers, Jerjerrod displayed minor spite and a deficiency in ambition as he advanced within the Imperial hierarchy. These qualities were surprisingly valued in a Moff. Jerjerrod, a technocrat with a cold demeanor, held the position of Commander of the second Death Star as it neared completion. He took pride in this role but also felt apprehensive due to the complexities of the station's construction. While he asserted that his subordinates were working with maximum effort to complete the station, the potential of facing the Emperor's displeasure due to the construction delays—a prospect that visibly unnerved him—prompted him to reassess the pace of the project. Jerjerrod exhibited respect in the Emperor's presence, kneeling upon greeting him and bowing before departing. Beyond the Emperor, Jerjerrod feared Vader, not wanting to have his name added to Vader's list of kills as there wasn't a single Imperial soldier who hadn't heard about the Sith Lord's predilection for strangling those who'd failed to carry out his orders. Despite this fear, he found Vader to be an important organizing principle - a kind of certainty that was fundamental to the Empire.
Jerjerrod was unpretentious, his quarters sparsely furnished with a standard-issue bed and a drafting table. Possessing an engineering background, Jerjerrod was attentive to detail. He preferred to store project specifications on flimsiplast instead of relying on datapads. Jerjerrod also appreciated music.

Michael Pennington played Tiaan Jerjerrod in Star Wars: Episode VI Return of the Jedi. Alan Rickman, a British actor, initially auditioned for the role of Jerjerrod, expressing a desire to portray him with a "Big, slow, low voice," but Pennington was selected instead. Although he is only referred to as "Commander" in the film, his name and official rank are provided in the end credits. Jerjerrod functions as a secondary antagonist with limited screen time and dialogue in the final film, although his role was more substantial in earlier versions of the script. The Moff is also featured in several scenes filmed for Return of the Jedi that were ultimately removed from the finished product. Some of these scenes, which form a subplot in which Jerjerrod is ordered by the Emperor to destroy Endor once the battle turns against the Empire (scenes retained in the novelization of the film), were included in the Star Wars: The Complete Saga Blu-ray set. Due to a props "blooper" during production, Jerjerrod and all other Imperial officers wear the incorrect rank badge in the film.
Jerjerrod's part in Return of the Jedi underwent considerable expansion and contraction during the script's development. Earlier drafts distinguished him as a tall Grand Moff and a self-assured technocrat, rather than just a Moff. In these versions, Jerjerrod acted as Emperor Palpatine's "secret agent," overseeing the transformation of the Green Moon of Had Abbadon into a paradise for its inhabitants while operating in secret from Darth Vader. While aboard Jerjerrod's shuttle, upon being informed, Jerjerrod denies the Rebel presence on the moon that Vader had sensed seeing it as an insult to his work, even as a stolen Imperial transport piloted by Leia Organa and two other Rebels nearly collides with the shuttle. Upon arriving on Had Abbadon, Vader and Jerjerrod descend to the Emperor's Throne Room. Once Vader departs, reprimanded for not capturing Luke Skywalker, the Emperor tasks Jerjerrod with keeping an eye on Vader as he planned to replace him with Skywalker, also revealing that the Rebels were launching an attack on the Death Star. Jerjerrod later butts heads with General Veers, who took Skywalker prisoner to the Executor instead. Furious, Jerjerrod stormed out to meet with the Sith Lord and demanded to know why Skywalker was not delivered to the Emperor, leading Vader to snap Jerjerrod's neck and kill him.
In Lawrence Kasdan's revised rough draft, Jerjerrod's shuttle nearly intercepts Leia's captured transport when it was moving to help a panicked Wedge Antilles flying a captured TIE Fighter during the strike team's infiltration without a clearance code. However, after Leia's craft was given clearance, Vader complains to Jerjerrod that the Emperor had not been in contact with him. Though Jerjerrod attempts to avoid an argument, he is forced to reveal that the Emperor, has reassigned Vader to oversee the construction of the two new Death Stars for not capturing Skywalker. Jerjerrod also doubted that Vader would be able to seduce Skywalker to the dark side of the Force unlike the Emperor. Jerjerrod too reveals that the Emperor knows of the impending Rebel attack, and that Skywalker would be soon captured at Tatooine. After conversing with the Emperor via hologram at the private communications chamber of the Executor, Jerjerrod takes the responsability to deliver Luke without Vader's knowledge by using coded transmission and siable all surveillance equipment, concluding that the Rebel attack was a distraction for Vader. Upon learning of this, Jerjerrod was killed by Vader.

For the Special Edition of Star Wars: Episode V The Empire Strikes Back, footage from Darth Vader's arrival aboard the Death Star at the start of Return of the Jedi was reused to depict Vader returning to the Executor after his duel with Luke Skywalker on Cloud City. Although the scene is shown from a different angle compared to its original appearance in Return of the Jedi, Michael Pennington can still be seen in the shot.