Tanis (born 2358) was an Ocampa male, who was elected by his ancestors to live with the Caretaker's mate, Suspiria. He believed that his longevity was owed to Suspiria's nurturing; Tanis was 14 years old, exceptionally old for an Ocampa, whose average life span was only nine years. His father lived to be 20.
However, he lacked the compassion the Caretaker's Ocampa had displayed, regarding the crew of Voyager, with their lack of psychic powers, as little more than pets. Tanis urged Kes to leave Voyager and live on the Ocampa space station, where he could teach her how to use her psychic abilities and she could live with her own kind. He attacked Neelix when the Talaxian tried to interfere. He was ordered to deliver Voyager to Suspiria who wanted revenge on the crew who she believed had killed her mate. Kes became aware of the plot and attacked Tanis with her psychic powers which also disabled Suspiria. When Suspiria returned to her home Exosia, Tanis followed with her. (VOY: "Cold Fire")