First's cube
This Borg cube, led by , was controlled by five assimilated children who had been separated from the Collective mind; they controlled a vessel that was normally run by five thousand drones. () It was disabled after the cube assimilated Icheb, who was carrying a pathogen that killed all of the adult drones. ()

This cube was encountered by starship 's away team that were on an away mission aboard the  in 2376. It attacked the Delta Flyer, which engaged in a skirmish with the attacking heavily damaged cube. The Delta Flyer was able to cause damage to the cube's propulsion matrix. The cube captured then caught the Flyer in a tractor beam pulling it into the vessel itself. 

Later the starship USS Voyager arrived on the scene after discovering the cube's occupants have taken Commander Chakotay, Ensigns Tom Paris and Harry Kim, and Neelix as hostages. The leader, First, ordered Captain Kathryn Janeway to surrender their deflector array so they could return and rejoin the Collective. Janeway refused to give them the array after Seven of Nine had told her that the Borg Collective would refuse to let these drones return due to the drones being unpredictable. The cube locked a tractor beam onto Voyagers deflector array by force, but the Voyager's crew sent a feedback which damaged the cube, after which, Voyagers crew was able to beam the away team off the cube. 

Seven of Nine tried to tell First to deactivate the beam or the cube would explode. First tried to kill Seven, but Icheb, one of the other drones, saved her from First. First tried to intervene but was killed by the feedback which had severely injured him. The young leaderless drones were able to deactivate the shields and tractor beam just in time. The cube was soon abandoned after Voyagers crew decided to adopt the four remaining drones. ()

Personnel 

Unnamed Borg starships