Nahdonnis Praji was a male Human, born into the affluent House Praji on the planet of Coruscant as the Galactic Republic neared its end. His birth occurred around the final years of the Republic. Around 19 BBY, Praji became a member of the Galactic Empire's newly formed navy, distinguishing himself as a graduate of the Imperial Academy on Carida. He took part in various Imperial operations, including the subjugation of Almak. During the Galactic Civil War, Praji commanded troops in battles against Rebel insurgents at Datar and Nar Shaddaa. These actions led to his appointment as aide to Lord Darth Vader on the Imperial Star Destroyer called the Devastator. In 0 BBY, following the Rebels' acquisition of the plans for the Death Star superweapon, the Devastator pursued the Alderaanian CR90 corvette known as the Tantive IV, the consular ship of Imperial Senator Leia Organa, to Tatooine. After the starship was captured and boarded above the planet, stormtroopers quickly took control, and Praji rushed to the main computer room to locate the stolen schematics.
The plans, however, had been copied into the memory banks of the astromech droid R2-D2. Accompanied by his counterpart, the protocol droid C-3PO, R2-D2 escaped the corvette in an escape pod that crashed on Tatooine. Praji informed Vader that an escape pod had been launched during the engagement, but reported that no life signs were detected. Vader instructed Praji to personally search Tatooine for the plans, but Praji instead delegated the task to his subordinates. He tasked Captain Kosh's local garrison, Captain Terrik's Desert Sands, and Vader's 501st Legion with locating the pod. While the planet's spaceports were placed under quarantine, the two droids, aided by Corellian smuggler Han Solo, moisture farmer Luke Skywalker, and Jedi Master Obi-Wan Kenobi, evaded the blockades and escaped aboard Solo's freighter into hyperspace, heading for Alderaan, Senator Organa's homeworld. Following the Battle of Endor four years later, Praji joined the forces of several Imperial warlords, ultimately serving under the resurrected Galactic Emperor, His Immortal Majesty Palpatine. His actions in the battle of Kaikielius earned Praji the position of governor of that planet.
Nahdonnis Praji, a Human male, came into this world as a member of the wealthy and influential House Praji on the capital planet of Coruscant, sometime after the initial months of 37 BBY. Griff Praji, his father, was the brother of Tannon Praji, who held the position of First Minister within the Coruscant Ministry of Ingress. Throughout his formative years, Nahdonnis Praji developed a strong interest in military history. He was known to frequently study reports from the HoloNet News that detailed the strategies employed by Jedi Generals and the accomplishments of starfighter aces during the Clone Wars. Before the Galactic Republic was dissolved in 19 BBY, the Praji family typically consisted of either idle, wealthy individuals or career bureaucrats. However, a few Coruscanti members of the Praji family chose to enter military service: Collin Praji achieved the rank of Colonel, and another Praji became the Moff in command of the Fourth Outer Rim Army. Several months following the end of the war, Praji reached the age of eighteen and enlisted in the Galactic Empire's newly formed navy. He completed his basic training and graduated with honors from the Academy located on Carida, a planet situated within the Carida system of the same name. The Praji family made donations of genetic templates for use in Imperial stormtrooper development programs. Nahdonnis Praji also had a child, a daughter named Tyla.

Praji was a participant in the subjugation of the native Leffingites on the planet Almak, and he had to concede that the Empire's All Terrain walkers, which he considered to be ungainly and brutish, were indeed effective. In 1 BBY, early in the Galactic Civil War, Praji received an assignment to the Imperial-class Star Destroyer Vengeance and was given the task of searching for Rebel supply networks. He later served under Vice Admiral Slenn, who ordered his troops into what became an unwinnable situation against the Rebels on the planet Datar. Following this unsuccessful attack, the Dark Lord of the Sith Darth Vader killed Slenn and assumed command of the operation.
Vader's subsequent objective was the Rebel base located on Nar Shaddaa, the moon of the Hutt planet Nal Hutta. Praji personally led the troops to the 88th Level of the moon's Corellian Sector, resulting in a substantial number of collateral kills. He employed a flanking maneuver that was once favored by Jedi General Anakin Skywalker, who had used it extensively during the Clone Wars. Praji's actions, along with his prior record, made a favorable impression on Vader, leading to his assignment to a staff position with increased responsibilities. He became Vader's aide aboard the Imperial I-class Star Destroyer Devastator, which meant he lost his permanent command post because the Devastator's troop complement was largely composed of elite stormtroopers from the 501st Legion, under the leadership of Commander Daine Jir.
In 0 BBY, on the planet Toprawa, the Rebel Alliance managed to obtain the plans for the first Death Star, a new superweapon developed by the Empire. The Toprawa system was declared a restricted zone, and Darth Vader, realizing that the plans had fallen into the hands of the Rebellion, brought the Devastator to the planet. The Rebels were planning to smuggle the plans off the planet on the Alderaanian consular ship Tantive IV. As the vessel entered the Toprawa system, it began receiving a transmission from the planet's surface. Commander Praji was present with Vader on the bridge of the Devastator when the sensors detected the consular ship. As the data was being transmitted, an Imperial communications officer detected the signal, and Praji contacted the Tantive IV, ordering it to stop and prepare for inspection. Attempting to buy more time, the Rebel Captain Raymus Antilles informed the Devastator about their "malfunction" and tried to invoke the vessel's diplomatic immunity. Praji acknowledged the message and instructed the Tantive IV to maintain its course and prepare for boarding.

Moments later, the transmission ended, and Antilles responded to the Devastator, asserting that they could not be detained because they were on a diplomatic mission. He also ordered his crew to accelerate the ship to full speed and enter hyperspace. Praji announced that they had detected the transmission of the plans and again ordered the Tantive IV to stop or be fired upon. Vader ordered the Star Destroyer to fire with minimal damage in mind, and shortly after the firing began, the Tantive IV jumped to lightspeed. Tracking a ship through hyperspace was impossible; however, the Tantive IV carried an Imperial homing device that had been installed during a previous trip to the planet Ralltiir. Praji consulted a sensor screen and reported that the Tantive IV was heading to the planet Tatooine.

The Devastator pursued and captured the Rebel vessel in the Tatoo system, where the troopers of the 501st legion laid siege to the crippled consular ship. Praji commanded a group of troops to the ship's main computer room to locate the stolen plans. He was assigned the task of checking the computers for the plans and any other useful information.
Praji employed the modified R4-series agromech droid, R4-M9, to extract all data from the memory banks before the Rebels could destroy it, but he found no valuable information or evidence of bank erasure. When Vader and Commander Jir arrived at the main computer room, Praji updated the Dark Lord on the search, reporting that the plans were not on board the ship and that no transmissions had been made. He added that an escape pod had left the ship, but no life forms had been detected. Vader instructed him to personally lead a detachment of stormtroopers to Tatooine and search for the escape pod used by protocol droid C-3PO and astromech droid R2-D2, the latter of whom was carrying the stolen plans. Vader also ordered Praji to send detachments to every spaceport and quarantine the planet.

Following Vader's orders, Commander Praji oversaw the search for the missing Death Star's plans on Tatooine. His initial directive was to assign Captain Kosh's local garrison to the task, while the 501st was prepared. The Desert Sands sandtrooper detachment, which had arrived to relieve the troopers stationed in the city of Mos Eisley, was also instructed by Praji to immediately begin searching for the escape pod. After a brief landing, Praji delegated overall command of the situation to Captain Kosh.
After several days of searching, Captain Mod Terrik of the Desert Sands informed Praji that a young moisture farmer, possibly a Rebel sympathizer or even an agent, had taken the droids and was likely headed to the nearest spaceport, Mos Eisley. In reality, the actions of the Desert Sands—murdering his uncle Owen Lars and aunt Beru Whitesun Lars—had caused the farmer, Luke Skywalker, to join Jedi Master Obi-Wan Kenobi in his mission to return the stolen plans to the Rebellion. Praji agreed with Terrik and ordered him to quarantine Mos Eisley.
However, the delay in coordinating the units of Kosh's troops, Terrik's troops, and the 501st allowed the droids to bypass the blockade and escape from Tatooine aboard the light freighter Millennium Falcon. A stormtrooper officer observed the freighter taking off and reported it to Commander Praji, who alerted the orbiting Star Destroyers. Han Solo, the Falcon's captain, managed to slip past the blockade, placing the Commander in the difficult position of reporting his failure to Vader. Praji also provided a description of the fugitives and their escape vessel to all Imperial outposts. He personally delivered the bad news to Vader, who spared his life.

Following the Battle of Yavin, in which the Rebels destroyed the Death Star using information obtained from the stolen plans, Vader established Death Squadron, a squadron of Star Destroyers that included the Devastator. Vader planned to bring his staff to his new flagship, the first ship in the Executor-class Star Dreadnought line, but General Maximilian Veers prevented Praji's appointment, and Vader did not override him.
During the Battle of Endor in 4 ABY, Emperor Palpatine was killed, leading to the fracturing of the Empire into various warring factions. Praji served under several different Imperial warlords and rose to the rank of General. He selected his allies based on which offered the best path to continue the New Order's mission. When the Galactic Emperor, His Immortal Majesty Palpatine, returned from the Deep Core of the galaxy, Praji joined his forces and met him in person for the first and only time.
Six years later, Praji led a portion of the Shadow Hand Fleet that conquered the planet Kaikielius before the push toward Coruscant at the beginning of Operation Shadow Hand. Praji took pleasure in destroying the skyhooks of House Vahali, an old rival of his family, and placed the planet under martial law. His elevated position made him realize that the Emperor's theocracy was not the same Empire he had joined decades earlier, so he requested Kaikielius as a fief in order to leave the military. Emperor Palpatine then appointed him as the Governor-General of the world, re-establishing the historical connection between Kaikielius and House Praji. After the Battle of Coruscant during the Yuuzhan Vong War, the Coruscanti Praji regrouped on Kaikielius. Praji later retired from his governorship and was interviewed by historian Voren Na'al, who inquired about his encounter with Emperor Palpatine. His daughter Tyla would later become a prominent member of the Galactic Alliance Guard during the Second Galactic Civil War.
Praji was all business when interacting with his superiors, although he was not always effective in carrying out orders, often delegating tasks to subordinates like Captain Kosh. He was known to rule his subordinates with a firm hand, and they recognized him for his intolerance and level-headed professionalism. He was not easily angered, and his calm and composed demeanor impressed his superiors and maintained order within his command. His businesslike professionalism also impressed Lord Vader. As a member of the capital's aristocracy, Praji held a disdain for Rimmers, those from the Outer Rim region of the galaxy, even if they were his superiors. He was a traditional military man who looked down on foot soldiers, partly due to Imperial officer training, which disregarded the clones, viewing them as expendable. He was so dedicated to the orderly despotism of the Galactic Empire that, during the Imperial Civil War, he served under multiple warlords, seeking the best way to continue the New Order's mission. Praji was known for wearing prominent sideburns, a style popular among Imperial officers around the time of the Battle of Yavin. He graduated with honors from the Imperial naval academy. Under capable officers like him, stormtroopers learned to adapt to their environments.

During the hunt for the blueprints of the Death Star, Praji stated to Vader in a monotone voice that the schematics for the Death Star were not located on the Tantive IV. He then hastily added that the escape pod, which was supposedly unoccupied, had been launched during the engagement. He paused, waiting for the Sith Lord to give his orders. Vader considered him too valuable and loyal to eliminate, and thus spared the Commander's life when Praji failed to personally search for the missing plans, directly disobeying his command. Praji never cared much for his family's long-standing feud with House Vahali, but he derived immense personal satisfaction from dismantling their power by destroying their skyhook headquarters during the Imperial Civil War.
His allegiance to the Emperor was steadfast until Operation Shadow Hand, at which point he discovered the Emperor's intentions to establish a theocracy ruled by Dark Side Mages. Throughout his career, he had heard claims that the Emperor suffered from delusions of grandeur, but he had always disregarded these assertions, viewing them as mere figures of speech or derogatory remarks from inferior individuals unable to grasp the true greatness of exceptional men. However, upon learning of the Emperor's theocratic ambitions, which directly contradicted the New Order he had served, he was compelled to reconsider his prior assessment of the Emperor's mental state. Praji had light skin, brown hair, and blue eyes.
Commander Praji was seen wearing the black version of the standard Imperial officer's uniform. His weaponry consisted of a blaster pistol as well as an E-11 blaster rifle.

The character of Praji initially appeared in the December 1976 novelization of Star Wars: Episode IV A New Hope, which was ghostwritten by Alan Dean Foster. George Roubicek portrayed the character in the 1977 film, though he did not receive credit for it. An American actor dubbed his lines, resulting in a voice that bore no resemblance to Roubicek's. The scene featuring Praji was filmed over three days in July 1976, near the end of principal photography, on the Tantive IV main corridor set on Stage 9 at Elstree Studios, located just north of London. This occurred before the movie was released on May 25, 1977. In the revised fourth draft script of A New Hope, which was included in 1998's Star Wars: Behind the Magic and 1997's Star Wars: The Annotated Screenplays, Praji is called "Second Officer," and Vader instructs Jir, rather than Praji, to "send a detachment down."
The Star Wars Customizable Card Game's Premiere Limited base set, released in 1995, was the first to identify the character by the name Praji. Later, the September 4, 2007 article "The Empire's Finest: Who's Who in the Imperial Military," penned by Daniel Wallace and Abel G. Peña and featured in the 96th issue of the Star Wars Insider magazine, was the first to refer to him as Nahdonnis. When the character Tannon Praji was conceived in 2005, he was intended to be Commander Praji's uncle. However, this detail was not revealed until 2009 in Nathan O'Keefe's article "Tinker, Tailor, Soldier, Praji," which established Nahdonnis as the son of Tannon's brother Griff and identified numerous other members of the Praji family.
During Celebration IV in May 2007, Roubicek participated in a round-table discussion moderated by Scott Chernoff, where he shared memories of his role as Praji. The other participants, all of whom portrayed Imperial characters, included actors Kenneth Colley (Admiral Firmus Piett), David Prowse (Darth Vader), Barrie Holland (Lieutenant Renz), Richard LeParmentier (Admiral Conan Antonio Motti), and Julian Glover (General Maximilian Veers). The conversation was subsequently published in Star Wars Insider 96.

Praji's character appears in several adaptations of A New Hope, but his dialogue and appearance sometimes vary. In the 1976 novelization, he delivers a different line and is described as the "officer in charge" of "a cluster of tired-looking troops." In the April 12, 1977 first issue of Marvel Comics's A New Hope adaptation, Praji is absent, and Vader orders Jir to dispatch the sandtrooper detachment to Tatooine to search for R2-D2 and C-3PO. In the 1978 Contemporary Motivators: Star Wars comic book, he is portrayed as a stormtrooper, and his line is slightly altered compared to the film. In 1978's The Story of Star Wars, he is identified as an Imperial trooper.
In the script for the 1981 Star Wars radio drama, which was published in 1994 as Star Wars: The National Public Radio Dramatization, Praji's line is attributed to a 'Trooper.' However, in the radio episode itself, the character delivering the line does not have a modified voice to match the stormtroopers, making it possible to identify him as Praji. Furthermore, an earlier scene in the episode features an Imperial commander hailing the Tantive IV near Toprawa and Tatooine. The 2007 young reader novel The Rise and Fall of Darth Vader by Ryder Windham later identified Praji as the commander in this scene. In the sixth issue of the 1986 Star Wars: Droids comic-book series, Praji delivers a slightly different line while wearing a gray uniform. The issue was written by David Manak, illustrated by Ernie Colón, and released on February 6, 1987.
In the 1997 young reader book Darth Vader's Mission: The Search for the Secret Plans by Jane Paley, Praji is depicted as blond and wearing a gray uniform. In the 1998 reference book Anakin Skywalker: The Story of Darth Vader by Stephen J. Sansweet, the captain of the Devastator hails the Tantive IV above Toprawa, but The Rise and Fall of Darth Vader attributes these lines to Praji. In 2008, Sideshow Collectibles released a Praji action figure as part of the Militaries of Star Wars set, which depicted him with brown eyes, contradicting the blue eyes he had in A New Hope. In A New Hope, Praji's rank insignia plaque consists of four blue tiles and two amber tiles. However, the action figure portrays Praji with four blue tiles and two red tiles instead of the amber tiles.
The non-canon comic book Tag & Bink Are Dead 1, released on October 3, 2001, features a scene where the protagonists, Tag Greenley and Bink Otauna, disguised as stormtroopers to escape Imperial custody, encounter Praji, who orders them to return to the Devastator. The issue was written by Kevin Rubio and illustrated by Lucas Marangon. In 2013, he made an appearance in the non-canon book William Shakespeare's Star Wars: Verily, A New Hope by Ian Doescher, where he spoke different lines and was referred to as a captain.