Parein

From Memory Alpha, the free Star Trek reference

The Parein were an intelligent species assimilated by the Borg. Prior to their assimilation, the Parein were enemies with the Farn. A number of Parein drones on a planet in the Nekrit Expanse, liberated from the Borg Collective, chose to resume their old conflict with the Farn. Their fighting continued until the neural link between them was re-established and they became part of the Borg Cooperative. (VOY: "Unity")