Kor Essen was a male Nagai scout and also a slave under the control of Phylus Mon. He is considered a character from the Legends continuity.
Prior to the Nagai invasion targeting the "Skyriver" galaxy, Kor Essen, a scout, along with his brother Vor, were dispatched to penetrate the galaxy's underworld of gambling and criminal organizations. Becoming captivated by this new way of life, the brothers chose to disregard their original assignment.
However, around 20 BBY, Kor and Vor Essen were eventually apprehended by Chevin slaver Phylus Mon. They were then confined within Mon's slave zoo aboard the vessel named Animiasma. Their primary desire was to find a way to break free.
The Essen brothers, in the event that potential rescuers appeared, would attempt to offer bribes consisting of self-made Tehk'la blades or electromesh armor. This was due to their belief that all beings were more motivated by tangible possessions rather than abstract moral principles.
Phylus Mon implemented a system where an explosive device was surgically implanted near the heart of each of his slaves. This explosive was designed to detonate upon Phylus Mon's death. However, it could also be disabled through the impact of an ion weapon. Additionally, the slaves held within Phylus Mon's zoo were subjected to regular beatings.
The maltreatment endured under Mon's control caused the brothers to reevaluate their position within galactic society. They managed to escape with other prisoners shortly before the Clone Wars began. Kor and Vor then resumed their initial mission, continuing to gather vital information in preparation for the planned offensive.