The Terror represented an Executor-class Star Dreadnought that served the Galactic Empire during the era of the Galactic Civil War. Commanded by Admiral Sarn, the Terror was tasked with safeguarding the development of a novel cloaking device intended for the TIE Phantom starfighter. Furthermore, the Terror itself was equipped with this cloaking technology, rendering it undetectable to both sensors and the unaided eye. During a visit from Darth Vader, the Dark Lord of the Sith, to observe the new starfighter's deployment in 3 ABY, two Rebel operatives managed to infiltrate the Terror. These infiltrators, known as Rookie One and Ru Murleen, successfully stole a TIE Phantom. Using this stolen fighter, they destroyed the Terror's main reactor while the vessel was docked at the TIE Phantom factory orbiting Imdaar Alpha. Lord Vader managed to escape the Terror just before the reactor's explosion, which obliterated the Star Dreadnought. However, before his departure, he executed Sarn for his perceived incompetence.
The Terror, an Executor-class Star Dreadnought measuring nineteen kilometers in length, stood as one of the Galactic Empire's most formidable battleships. Mirroring its counterparts within the same class, the Terror displayed a gray hull exhibiting a distinct arrowhead-like shape when observed from above. The upper surface of the ship featured a streamlined hull that encompassed a central "island" of habitable sections, complemented by a trapezoidal command tower situated towards the aft. Conversely, the underside was characterized by a complex network of superstructure elements and thirteen red-glowing engines responsible for propelling it through space.
Upon its assignment to the TIE Phantom project, the Terror underwent retrofitting with a cloaking device powered by stygium crystals. This cloaking technology rendered the Terror invisible to both the naked eye and the sensor arrays of other starships. Imperial vessels approaching the Terror were required to transmit a specific security code before the ship would deactivate its cloak to permit docking. As the cloaking device was disengaged, the Terror would materialize into view progressively from bow to stern, with the entire process concluding in under ten seconds.
The Terror was designed to function as a carrier for the Empire's contingent of TIE Phantoms. A connected series of service hangars, partitioned by blast doors, housed hundreds of these cloaking-equipped starfighters mounted on racks lining the walls. Mechanical arms were employed to extract each TIE Phantom from its rack, preparing it for launch or maintenance procedures. The fighters could be transported around the ship via ceiling-mounted rails that traversed expansive chambers, crisscrossed by walkways and retractable bridges. Additional hangars were positioned on both sides of the ship, facilitating access for shuttles and other spacecraft. In addition to the TIE Phantoms stationed on board the Terror, at least one of these hangars was equipped to store a number of TIE interceptors suspended from the ceiling.
The Terror's bridge, located within the command tower, featured two crew pits separated by a walkway leading to the expansive forward viewports. The ship also incorporated a meditation chamber for the use of Darth Vader, the Dark Lord of the Sith. This pressurized, spherical chamber contained equipment that allowed the Sith Lord to swiftly remove and replace his iconic helmet. The Star Dreadnought possessed its own integrated sewer system, comprising a network of interconnected tunnels through which waste material flowed beneath walkways. Access to the sewers was provided by access panels situated in the floor of the deck above.
The ship's main reactor was housed within a circular chamber surrounded by beam focusers designed to prevent critical failures. Access to the reactor was possible via a network of large tunnels that ran throughout the superstructure. These tunnels, filled with moving machinery and periodically segmented by force fields powered by shield generators, were sufficiently large to allow a starfighter to navigate through them. At least one such tunnel extending from the reactor core led to the exterior of the ship.
The Terror was among the Super Star Destroyers built by the Galactic Empire during the Galactic Civil War, entering service under the command of Admiral Sarn by the year 3 ABY. For several years, Grand Admiral Martio Batch had dedicated his efforts to developing a functional cloaking device at his research facility located on the moon Imdaar Alpha. Cloaking devices, once commonplace, relied on stygium crystals mined from Aeten II within the Dreighton Nebula. Following the depletion of these mines, the technology fell into disuse until Batch utilized the Empire's Tarkin superweapon to destroy Aeten II, releasing thousands of stygium crystals into space. Batch then embarked on a project to utilize these crystals to produce a squadron of cloaked starfighters – modified V38 assault fighters known as TIE Phantoms. The Grand Admiral requisitioned the Terror to serve as the command ship for a fleet that included at least two Imperial-class Star Destroyers, tasked with protecting the project. The Star Dreadnought itself was outfitted with a cloaking device and configured to serve as a carrier for the TIE Phantoms.
Following the Imperial triumph over the Alliance to Restore the Republic at the Battle of Hoth in 3 ABY, Darth Vader, the Dark Lord of the Sith, visited the Terror to supervise the final operational trials of the new starfighters. From aboard the Star Dreadnought, Vader observed as TIE Phantoms from Sigma Squadron intercepted and annihilated a flight group of Rebel X-wings patrolling the Dreighton Triangle, a region of space. Upon the conclusion of these trials, the Dark Lord instructed Sarn to return the Terror to Imdaar Alpha, initiating the final preparations for deploying the TIE Phantom fleet against the Rebellion.
The Rebel Alliance intercepted information regarding the Empire's scheme and dispatched pilots Ru Murleen and Rookie One to Imdaar with the mission to infiltrate the Terror and secure a TIE Phantom for analysis. As the Terror approached Imdaar, preparing to dock with Batch's cloaked facility, the Rebels, using a supply shuttle pilfered from the supply platform located on the planet, were granted docking permission. Despite their eventual discovery, the intruders utilized the Terror's sewer system to evade capture, ultimately reaching a service hangar where they commandeered a TIE Phantom. The Imperials promptly sealed the outer bay doors to thwart their escape, but the Rebel pilots skillfully navigated the stolen fighter through the Star Dreadnought's internal structure, reaching the main reactor and destroying the surrounding beam focusers before successfully escaping. As the Terror's reactor began to destabilize, Vader executed Sarn for his failure before evacuating the doomed Star Dreadnought. The reactor detonated shortly thereafter, resulting in the Terror's destruction. The resulting explosion exposed the TIE Phantom factory, enabling the Rebels to infiltrate and destroy it, thereby terminating the TIE Phantom project.
During its involvement in the TIE Phantom project, the Terror was under the command of Admiral Sarn, reporting to Grand Admiral Martio Batch, a high-ranking officer within the Imperial Navy. As the operational testing phase of the new starfighters neared completion, Darth Vader, the Dark Lord of the Sith, assumed overall command of the project, operating from the Terror. The Star Dreadnought's complement included a large number of stormtroopers and pilots, in addition to various models of droid, including MSE-6-series repair droids, R2-series astromech droids, and remotes.
Vincent Lee conceived of the Terror for the 1995 LucasArts video game Star Wars: Rebel Assault II: The Hidden Empire. Within the game, the Terror is only described as a "command ship." Later resources identified it as a Super Star Destroyer. However, The Essential Guide to Warfare clarifies that this term encompasses multiple classes of vessels, and it is among several sources that classify ships of the Terror's design as Executor-class Star Dreadnoughts.