Rebi was a Wysanti and one of the four Borg children rescued by the USS Voyager in 2376. He and his twin brother, Azan, had been assimilated by the Borg several years previously. After the Borg cube he was on was disabled by a pathogen, he and the other children were taken on board Voyager where former Borg drone Seven of Nine helped him to regain his individuality. Azan and Rebi left Voyager when the starship encountered their people, the Wysanti. Mezoti also left the ship, to live with the twins.
While on Voyager, Rebi and Azan worked together on a project for the first Annual Voyager Science Fair. Their original idea was to clone Naomi Wildman. However, on recommendation from Seven of Nine, they chose to clone a potato instead.
Rebi usually wore a red shirt and blue overalls.