Horzao Darr, a Human male, hailed from the remote planet of Exocron. This world is situated within the Kathol Outback, a largely unexplored region of the galaxy found in the Outer Rim Territories. As an officer within the Exocron Airfleet, he was a well-regarded and proficient sky-sailor, commanding the flagship, a sky-dreadnaught called Maxion. In 8 ABY, Captain Darr initiated first contact with the New Republic when the CR90 corvette FarStar inadvertently stumbled upon Exocron while searching for the renegade Imperial warlord, Moff Kentor Sarne. To safeguard the planet, the ruling homeworld caste, known as the Devisors, decided to prevent the New Republic delegation from ever leaving Exocron. Disgusted by this decision, Darr came to the rescue of the stranded crew, joining forces with the local insurgents to liberate Kaiya Adrimetrum, the FarStar's commander. This act of defiance ultimately resulted in the end of the Devisors' reign, liberating Exocron from their technocratic control.
Darr remained in military service, achieving the rank of Supreme Admiral by 19 ABY. He held command of the Exocron Combined Air-Space Fleet, the evolved form of the Exocron Airfleet where he had served years earlier. During the attack on Exocron, he led the defense against the Rodian Rei'Kas and his pirate fleet. They were repelled thanks to assistance from the Aing-Tii, a mysterious race of Force-sensitive aliens originating from the Kathol Rift.
Horzao Darr, a Human male, was born and brought up on the planet of Exocron, a world concealed within a protostar gas cloud in the Kathol Outback within the Outer Rim Territories. The ruling Devisors, a technocratic caste, kept Exocron isolated from the galaxy and restricted space travel, leading to the development of airships for both military and commercial use. At twelve, Darr became a stowaway on a sky transport. After being discovered, he began his career as a sky-sailor, essentially indentured to the captain to pay for his passage. He acquired the necessary skills to become a valuable crew member, continuing to work on the private vessel for several years before enrolling in Exocron's Airfleet Academy. Darr graduated with honors, receiving an officer's commission in the Exocron Airfleet and command of the air-cutter Loristar.

During Exocron's internal conflicts, when rebellious groups challenged the Devisors and the ruling council for planetary control, Darr, in command of the Loristar, undertook a mission to deliver crucial supplies to council forces under duress, battling his way through enemy lines to reach them. As a reward for his bravery, he was promoted to command of the Airfleet's flagship, the sky-dreadnaught Maxion. This new role thrust Darr into a world of politics and controversy. Some military insiders sought to elevate him to the rank of Supreme Admiral, granting him command of the entire Airfleet, hoping to use him to wrest power from the council. However, Darr consistently resisted these attempts, preferring to remain in the skies aboard the Maxion rather than be confined to a dreary council office.
Despite his loyalty to the Airfleet, Captain Darr held reservations about the Devisors, believing they were denying Exocron's people their rightful place. He knew they concealed the secrets of space travel from the public and abused their power by manipulating the ruling council, maintaining absolute control over the planet. This situation fueled rebellion, ranging from a quiet underground insurgency to outright aggression by Corsairs operating from the planet's western canyons. Darr kept his feelings hidden, though he was aware of several individuals involved in the insurgency, including his friend Eida Sharden. However, he disagreed with the insurgents' more extreme views and kept them at arm's length.
In 8 ABY, Darr and the Maxion encountered several strange aircraft in Exocron's airspace. Initially mistaking them for rebellious Corsairs, he ordered them to stand down and land on the Maxion, threatening destruction if they refused. The craft, X-wing starfighters from the New Republic CR90 corvette FarStar, complied and landed on the Maxion's flight deck. Darr met with the pilots, learning they were offworlders searching for a probe droid deployed to survey the planet as part of their mission to locate the rogue Imperial warlord, Moff Kentor Sarne. After a formal greeting, Darr apologized for his initial abruptness. He explained that their probe droid had been recovered by the Exocron Airfleet cruiser Desaclates and that he was ordered to escort them to the planetary capital, Caballa City. Eager to meet more offworlders, Darr permitted one X-wing pilot to return to the FarStar to inform their superiors and invite a delegation to the Maxion. From there, they would be transported to Caballa City to meet with the Devisors and the ruling council.

Kaiya Adrimetrum, the commanding officer of the FarStar, accepted Darr's invitation and accompanied a delegation to the Airfleet vessel. During the journey to Caballa City, Darr hosted a formal banquet aboard the Maxion for Adrimetrum and her delegation. During the meal, Darr received news that the Desaclates was under attack by Corsairs. Knowing the cruiser carried the FarStar's probe droid, he requested the assistance of Adrimetrum's starfighters, recognizing their superiority in speed and technology over the Skylark skyfighters on his vessel. Adrimetrum agreed as a gesture of goodwill, and Darr ordered the Maxion to proceed at full speed to the Desaclates. Upon arrival and discovering that the X-wings had successfully driven off the Corsairs, Darr personally commended them for their actions.

Upon reaching Caballa City, Darr escorted Adrimetrum to a meeting with the ruling council at the Ministry of Technology. In a private meeting, Pagda Gevtes, the Master Devisor, informed Darr of the Devisors' plan to confine the FarStar crew to Exocron for life and impound their starship for research, claiming it was to protect Exocron's safety and isolation. Darr recognized this as a ploy by the Devisors to maintain their power and expand their control through advanced technology. The Devisors ordered a powerful tractor beam in Caballa City to lock onto the FarStar, slowly pulling it down from orbit. They also decreed Adrimetrum's imprisonment for interrogation. Disagreeing with this decision, especially given Adrimetrum's assistance in defending the Desaclates, Darr finally acted on his inner feelings and resolved to help Adrimetrum and the FarStar crew.
As Adrimetrum was led away, she exchanged glances with Darr. Before the council guards could remove the rest of the FarStar delegation, Darr ordered his own troops to secure them and remove them from the chambers. Despite their surprise, the council guards did not question Darr's authority and allowed him to leave with the New Republic representatives. Darr took the FarStar delegation to the home of his friend, Eida Sharden, on the outskirts of Caballa City. Sharden introduced her guests to other members of the insurgency, representing the planet's political, financial, and intellectual elite, who agreed to assist in Adrimetrum's rescue. In return, Sharden requested data on spaceflight and navigational computers to enable Exocron's people to reclaim their birthright. A tentative agreement was reached, pending Adrimetrum's authorization for the information release.

With assistance from Sharden and the insurgency, Darr devised a two-pronged assault. One assault would target the tractor beam generator locked onto the FarStar. The insurgents knew its location, and the proton torpedoes from the FarStar's captured X-wings were needed to destroy it. A second assault would involve invading the Ministry of Technology to free Adrimetrum. Darr's involvement was crucial to both plans. Contacting the Maxion, Darr ordered it to a rendezvous point near Sharden's home. He introduced the members of the FarStar crew tasked with rescuing Adrimetrum to the Master Sergeant of the Maxion's cloud-jumper regiment, an elite unit specializing in using repulsorlift personal jump packs for enemy strikes. The Maxion would serve as an insertion platform, allowing a strike force to infiltrate the Ministry using the jump packs.
However, Darr would not accompany the Maxion on the insertion mission. Using his authority, he escorted the New Republic pilots to the military hangar where their starfighters were being held. Claiming to be inspecting the fighters with the New Republic pilots, Darr passed through the guards without suspicion. His ruse was only discovered when a Devisor arrived with several apprentices to study the starfighters. A firefight ensued, but the New Republic pilots prevailed and launched their starfighters. Both assaults were successful, and troops from the Maxion arrived at the Ministry of Technology in time to arrest Master Devisor Gevtes, who had personally attempted to stop the FarStar crew from rescuing Adrimetrium using a personal walker. After the Devisors' downfall, Adrimetrum personally thanked Darr for his trust and assistance.

By 19 ABY, Darr had attained the rank of Supreme Admiral, finally accepting the position many had urged him to take earlier. He held overall command of the Exocron Combined Air-Space Fleet, the successor to the Airfleet. When the Rodian pirate and slaver Rei'Kas—motivated by the planet's wealth and resources—threatened Exocron with his fleet, Darr delegated command of the space forces to Admiral Trey David, while he prepared the Airfleet ships in case Rei'Kas's forces breached the perimeter. Darr maintained contact with Jorj Car'das, a former smuggler who had retired to Exocron after spending over a decade with the Aing-Tii, a mysterious sentient species with a unique understanding of the Force. Car'das had studied their philosophy and Force control, and the aliens had pledged to protect him if needed. Darr arranged for the orbiting fleet to retreat before engaging the enemy, drawing Rei'Kas's forces closer to the planet. The Aing-Tii honored their agreement with Car'das, using their unique stardrives to appear behind the pirates, surprising and destroying them.
Horzao Darr was a capable military leader who rose to command based on merit, not favoritism, and was skilled in air vehicle combat tactics. An honorable and loyal individual, Darr upheld his oath to the Airfleet, even when it meant supporting a regime he personally believed was denying Exocron's people their rights. He resisted promotions to flag rank for years, preferring to remain an airship commander. Darr harbored doubts about the Devisors and knew of several insurgents, but kept his distance, deeming their views "too radical." The Devisors' harsh treatment of the FarStar crew finally pushed him to oppose them and support the insurgents. Captain Kaiya Adrimetrum had risked her crew to defend the Desaclates, and Darr felt she and her people had been treated unfairly. Darr was also practical, realizing that the FarStar and its advanced technology offered the best chance to defeat the Devisors. Darr's sideburns reached his jawline, and he appeared to be a natural fit for a uniform.
Horzao Darr was trained in personal defense, experienced in melee combat, and proficient in the use, maintenance, and repair of slugthrower weapons. He was also trained with missile weapons and in first aid. Darr could operate hover and repulsorlift vehicles and repair the latter. He was skilled in using Exocron's communication and security systems and possessed extensive knowledge of his homeworld's bureaucracy and culture. He was also knowledgeable about the Exocron system, despite never having left the planet by 8 ABY.
Horzao Darr wore the elaborate uniform of the Exocron Airfleet, befitting his rank, including a high collar, shoulder boards, and a sash. He always carried a slugthrower pistol, ceremonial sword, and comlink while on duty. Darr smoked a steam pipe, which he kept inside his uniform tunic. He puffed on the pipe while listening to the New Republic pilots who landed on the Maxion.

Horzao Darr first appeared in the roleplaying adventure The Masters of Exocron, part of The Kathol Outback supplement released on January 15, 1996. The Kathol Outback was part of The DarkStryder Campaign, a multi-book adventure published by West End Games. The Masters of Exocron was authored by Tony Russo and illustrated by Storn Cook. Horzao Darr's only other appearances in Star Wars literature were references in Timothy Zahn's novel Vision of the Future. Zahn had contributed to The DarkStryder Campaign, writing the story The Saga Begins for the first book in the series.