The Stalker functioned as an Imperial-class Star Destroyer within the structure of the Imperial Navy. Integrated into the Galactic Empire's Death Squadron, the Stalker held a position in the Juris sector along with fellow starships of the group when a probe droid, deployed under the umbrella of Project Swarm, communicated its finding of a Rebel Alliance base situated on Hoth. Following the Battle of Hoth, the Stalker played a role in the pursuit of the rebel freighter known as the Millennium Falcon, and it was one of the three Star Destroyers that almost collided during this chase: the Falcon, while being pursued by the Avenger, used its superior maneuverability to evade both the Stalker and the Tyrant as they approached from the opposite direction. Despite the three capital ships averting a catastrophic collision, the Falcon successfully escaped to the nearby planet of Bespin.
The Stalker, an Imperial-class Star Destroyer, came equipped with a hangar bay, a communications tower, a solar ionization reactor, and a pair of deflector shield generator domes. With a length of 1,600 meters, its propulsion was supplied by three destroyer-I ion engines along with four gemon-4 ion engines for use in emergencies.
In the year 3 ABY, the Stalker was actively serving within the Imperial Navy. Subsequent to the activation of Project Swarm, a Galactic Empire initiative that involved deploying Viper probe droids across the galaxy to pinpoint the secret base of the Rebel Alliance, the Stalker formed a part of Death Squadron. This squadron represented the personal fleet of Darth Vader, the Dark Lord of the Sith. The squadron, consisting of the flagship Executor, along with the Avenger, the Conquest, the Devastator, the Stalker, and the Tyrant, was positioned near Qeimet within the Juris sector when one of the deployed probes discovered the Alliance's main headquarters, Echo Base.
During 3 ABY, one of the probes launched from the Star Destroyer managed to reach the ice planet Hoth, which concealed the location of the Rebel's Echo Base. The probe successfully identified the base, which in turn, resulted in the Empire forcing the rebels to evacuate the planet. Following the battle, the Avenger joined the pursuit of the Millennium Falcon within the confines of the Hoth asteroid belt.
Death Squadron then executed a jump to hyperspace and eventually materialized within the Hoth system of the Anoat sector, the location of the base. The ISD Ultimatum joined the fleet and participated in the Battle of Hoth alongside the rest of Death Squadron. After the rebels evacuated from Hoth, Death Squadron engaged in the pursuit of the rebel freighter Millennium Falcon, which carried the key Alliance leader Princess Leia Organa. As the Avenger and its contingent of TIE fighters pursued the Falcon, the Tyrant and the Stalker moved in from the opposite direction. The Falcon executed a maneuver that brought the Tyrant and Stalker into a near-collision course with the Avenger. Despite being pursued by the Imperial fleet, the Falcon successfully escaped into the Hoth asteroid belt, and ultimately made its escape to Bespin which was situated nearby.
The initial appearance of the Stalker was in the 1980 original trilogy film, Star Wars: Episode V The Empire Strikes Back. While the Star Destroyer wasn't identified by name in the film, it was later given the name Stalker within the new Star Wars canon in the 2016 reference book titled Star Wars: Complete Locations. Within the Star Wars Legends continuity, the name was first introduced in the Star Wars Customizable Card Game's Hoth Limited expansion, which was released in 1996.
Although Star Wars: Complete Locations identifies the Star Destroyer responsible for deploying a probe droid to Hoth as the Stalker, the vessel was identified as the Avenger in Star Wars Character Encyclopedia: Updated and Expanded, published earlier in 2016, and in the ninth issue of Star Wars Helmet Collection. The Odyssey of Star Wars: An Epic Poem, a 2021 original trilogy adaptation written by Jack Mitchell, confirmed the canonical existence of the Stalker. This article operates under the assumption that Complete Locations provides the correct name, given that it is the more recent source.