Kes (2369-2378) was an Ocampa female who escaped from the Ocampan civilization and was taken prisoner by the Kazon-Ogla in 2371. After being tortured for being viewed as ugly by the Kazon for a span of time, Neelix rescued her and while both were under pursuit by the Kazon, the Caretaker moved Neelix's ship to the Alpha Quadrant, where they ran into the Terran Rebellion and Intendant B'Elanna of Ardana.
After the Terran Rebellion escaped from the station, Kes was taken by Tuvok to Memory Omega, where she was trained to develop her mental powers. (VOY - Mirror Universe novel: The Mirror-Scaled Serpent)
She and Tuvok later put her powers to the test during a failed attempt to assassinate B'Elanna. Kes also became distrustful of Tuvok during this time. (VOY - Mirror Universe short story: "Bitter Fruit")
In 2378, she escaped and took a ship to Terok Nor, where she used her mental powers to convince Neelix to come along. Tuvok, using a mental device installed into her brain, turned off her powers and took her prisoner as Terok Nor was destroyed by the Klingon-Cardassian Alliance. While the Terran Rebellion's armada battled the Klingons and the Cardassians in the Bajor system to try and prevent the Klingons from destroying Bajor's sun, Kes was freed of her device and destroyed the Cardassian fleet. She then proclaimed herself Empress and began torturing Tuvok but was almost immediately killed when the mental device in her brain imploded. (ST - Mirror Universe novel: Rise Like Lions)