Octanti

The Octanti (known to the Borg as Species 6339) were a technologically advanced sentient humanoid from the Delta Quadrant. They originated Grid 124, Octant 22-theta, circa 50,000 light-years from Earth. 

History
In 2371, the Octanti made first contact with the Borg Collective. The Borg began assimilating the Octanti, and the Octanti resisted.

On stardate 52356.2 (May 11, 2375) made first contact with the Federation when they encountered USS Voyager). By this time 11 billion Octanti had been assimilated by the Borg. Voyager asked the Octanti to help one of its crewmen, the former Borg drone Seven of Nine. The Octanti had allowed some of themselves to be assimilated by the Collective to infect a vinculum, which they hoped the Borg would retrieve to spread the disease unwittingly. Captain Kathryn Janeway eventually persuaded Ven to aid them. Voyager learned their remaining vessels were well-armed with phaser cannons.  In early 2410, Klingon Imperial Intelligence officer Galera briefed Klingon Defense Force commanders on the Octanti by sharing Octanti Intelligence File 3241-M as part of Operation Delta Rising. The file stated only a handful of Octanti escaped from assimilation. Only those on the starships of the Octanti fleet survived. By the early 25th century their numbers were still dwindling but the Octanti were committed to kill all Borg, including liberated Borg. Galera concluded an alliance with the Klingon Empire was possible as long as the Klingons would not interfere with the Octanti's mission.