Brunali adolescent male who was assimilated by the Borg and then "adopted" by the U.S.S. Voyager after being abandoned by the Collective.

Icheb — abducted from a Class-1 transport in Grid 649 — was one of several neo-natal drones left to fend for themselves on a Borg Cube that was infected by a virus that killed all the adult drones aboard in 2376. He had the designation "Second," despite the fact that he was the first of the neonatal drones to emerge from the maturation chambers; Icheb could not establish order among the young Borg, so he was relegated to "Second" while another adolescent took on the role of "First." This mini-Collective attempted to acquire Voyager's deflector in order to contact the main Collective, not aware that the Hive declared them damaged and irrelevant and had no intention of recovering them. After failing to assimilate Voyager, Icheb and the other Borg children joined the Federation ship's crew, whose Doctor removed most (but not all) of their cybernetic implants. They began schooling under the tutelage of Seven of Nine, also an ex-drone, while the crew searched for the children's original homes.

Icheb impressed Captain Janeway and Seven with his intelligence and initiative, and hoped to earn a permanent post in Voyager's Astrometrics lab. But his ambitions were cut short when his parents, Leucon and Yifay, were located, and Janeway arranged for him to reunite with them and other Brunali in an agrarian encampment on a Borg-devastated planet. The transition for Icheb was difficult, but he learned to accept his new life. However, once Voyager left the Brunali planet, Icheb's parents sent him off in a ship toward a transwarp conduit, intentionally trying to attract a Borg vessel. It turns out that Icheb had been specially bred with a genome to produce a pathogen to kill Borg — in fact, he was the carrier of the virus that disabled the Cube he and the other children were occupying. Voyager rescued Icheb from re-assimilation, suppressed the pathogen and kept him on board permanently.

The following year, Icheb stayed aboard as the other ex-Borg children left Voyager to make their home with the Wysanti race. Inspired by contact with the Alpha Quadrant through datastream transmissions, Icheb decided to apply for Starfleet Academy. He would take the entrance exam and forward it to Earth in a datastream, and if he passed, he would take the basic classes from Commander Tuvok (a former instructor at the Academy). His plan was put on hold when Seven of Nine's cortical node began to malfunction, threatening her life, and Icheb offered to transplant his own cortical node to her, convinced he could survive without it. More concerned about Seven's life than his own health, Icheb virtually forced Janeway and the Doctor to transfer his node to Seven. After the operation succeeded, Seven promised to help him prepare for his Academy exam.

Icheb's acclimation to individuality has been gradual; his manner is still very staid, but he continues to exhibit signs of normal humanoid development for a young man his age. In fact, he has begun to experience attraction toward the opposite sex and the inevitable confusion that accompanies it. He once surprised Lt. Torres with a declaration that they should "stop seeing each other"; he apparently developed a "crush" on Torres while working closely with her during a maintenance overhaul, and misread her gestures of friendship as romantic overtures.

A very bright young man, Icheb became quite adept at the Vulcan game of Kal-toh, and was once even able to beat Tuvok. In 2378 the Alpha Quadrant became Icheb's new home, as he remained on Voyager when the starship finally returned to Earth, at which time the ex-Borg drone planned to seek admission to Starfleet Academy.