NK-33 functioned as a droid bodyguard, assigned to Tyresius Lokai, who was a Devaronian smuggler. Lokai lived during the era known as the Cold War, a period of tension between the Galactic Republic and the re-emerging Sith Empire. This droid was a personal droid for Lokai.
During the year 3643 BBY, Lokai found himself a hunted target within the Great Hunt, leading him to seek refuge on Tatooine. After managing to evade capture on multiple occasions, a bounty hunter finally located and confronted Lokai. NK-33 engaged the hunter in combat, ultimately resulting in the droid's destruction. Nevertheless, Lokai and the bounty hunter reached an agreement, and the Devaronian became an associate of the hunter.