Tanis (born 2358) was an Ocampa male, who was elected by his ancestors to live with the Caretaker's mate, Suspiria. Tanis lived until he was fourteen years old, exceptionally old for an Ocampa, whose average life span was only nine years. He believed his longevity was owed to Suspiria's nurturing. Tanis' father lived to be twenty.
However, Tanis himself lacked compassion that the Caretaker's Ocampa had displayed, and he thus regarded the crew of USS Voyager, with their lack of psychic powers, as little more than pets. Tanis urged Kes to leave Voyager and live on an Ocampa space station, where he could teach her how to use her psychic abilities and she could live with her own kind. When Neelix tried to intervene, Tanis attacked him. Tanis was ordered to deliver Voyager to Suspiria, who wanted revenge on the crew, as she believed they 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 of Exosia, Tanis followed her there. (VOY: "Cold Fire")