Hunter-killer droid
The hunter-killer droid functioned as a security droid employed by the government of the planet Ikkrukk, which was situated in the Mid Rim. During the New Republic Era, these hunter-killer droids were integrated with ground-based cannons and orbital weaponry, together forming Ikkrukk's defense systems. In 34 ABY, Ikkrukkian sympathizers who supported the First Order intentionally disabled these defenses, along with all other defensive measures on Ikkrukk. Consequently, the First Order was enabled to attack Ikkrukk during their conquest of the galaxy.
Concurrently, General Leia Organa of the Resistance sent Black Squadron to Ikkrukk with the aim of establishing an alliance with the Ikkrukkians. The starfighter group arrived as the First Order's assault was underway, and Jessika Pava, a pilot within Black Squadron, suggested that the planet's formidable defenses, including the hunter-killer droids, may have been the reason Organa wanted to form an alliance with Ikkrukk.
Behind the scenes
The hunter-killer droid model was initially referenced in Poe Dameron 30, a comic penned by Charles Soule and released by Marvel Comics on August 15, 2018. Previously, various droids bearing the "hunter-killer" title had made appearances in the Star Wars Legends continuity, starting with the Hunter-Killer probot featured in the 1992 comic Dark Empire 5.