The Borg were a pseudo-race of cybernetic beings, or cyborgs, from the Delta Quadrant. No truly single individual existed within the Borg Collective (with the possible sole exception of the Borg Queen), as they were linked into a hive mind. Their ultimate goal was perfection through the forcible assimilation of diverse sentient species, technologies, and knowledge. As a result, they were among the most dangerous and feared races in the galaxy.
The physiology of each Borg drone varied according to the species from which it was assimilated. Drones were typically humanoid, although the Collective has demonstrated a willingness to assimilate non-humanoid life forms. Upon assimilation, a drone would cease to grow body hair and develop an ashen, grayish skin coloration, ignoring original skin pigmentation. Cybernetic implants would be either surgically attached to the body or grown internally by nanoprobes injected into the bloodstream. The nature of these implants varied from drone to drone, depending on its intended function, but basic nodes of cordical, interlink & cortical array are implemented in every drone. In certain cases, parts of the body such as an eye or an arm would be amputated altogether to make room for the cybernetics. The implants of a fully assimilated drone allowed it to function for extended periods without shelter, food, water, or even air. A drone's only requirement would be a supply of energy to maintain the implants that in turn maintained its biological functions. This energy would be supplied during regeneration cycles within a Borg alcove. Upon receiving damage, drone would return to the cove for assessment of the damage. Severely damaged drones would be disassembled and scavenged for reusable parts.
Borg drones were equipped with a myriad of technologies integrated into their bodies which enabled them to perform their duties within the Collective, several of which were universal to all drones. A neural transceiver kept them connected to the hive mind. A personal force field protected each drone from most energy-based attacks. As of 2373, each drone possessed a pair of assimilation tubules embedded in one hand for the purpose of instantly injecting individuals with Borg nanoprobes. A cortical processor allowed a drone to rapidly assimilate visual information. Borg drones were also equipped with a neural processor, which kept a record of every instruction that particular Borg receives from the collective hive mind. Drones also contained failsafes designed to deactivate and even vaporize their own bodies, thereby allowing the Collective to eliminate damaged or dead drones without leaving remains to be exploited by outsiders.