The Drifter's Ghost
From Destinypedia, the Destiny wiki
The Drifter's Ghost is the nameless Ghost partnered to The Drifter. Though it typically keeps itself hidden, it is distinguishable by its red eye and inability to speak, both of which are the result of extensive modifications that granted it access to a broader spectrum of Light and the ability to manipulate Darkness.
The Ghost raised the man who would eventually be known as the Drifter during the Dark Age, and immediately found him intractable. When it advised him to head towards a nearby settlement where they would find allies, the Drifter began running in the opposite direction and was promptly run over by a vehicle piloted by a Risen raider. The Ghost rammed through the Risen's skull, killing him, before reviving the Drifter and again advising him to join with its friends in the settlement. When the Drifter again went in the opposite direction, his Ghost had no choice but to follow.
Refusing to give either himself or his Ghost a name, the Drifter continued to reject his Ghost's advice and assistance even if doing so harmed him. His Ghost respected his wishes in that regard, and would allow him to die if his stubbornness killed him, though it would always bring him back afterward. 
Eventually, the Drifter settled in a village called Eaton, adopting the name Germaine and attempting to live as a normal person. "Germaine" would indirectly bring food to the hungry village by scouting for game with his Ghost and then secretly driving it in for his friend Judson to catch. However, on one scouting mission, the Ghost "got carried away" and was detected by a Warlord, the Red Man, leading him and his forces into an ambush by a contingent of Iron Lords under Lord Dryden. The ensuing battle razed Eaton and left Drifter the village's sole survivor. His Ghost recorded the disaster from above. In the aftermath, at the Drifter's request, his Ghost found him a spade to bury the bodies with. The Ghost reprimanded him for "[playing] house with refugees" and wasting his potential, but was ignored.
Later, the Ghost kept the Drifter from freezing to death when he climbed Felwinter Peak to personally condemn Dryden (the battle's only survivor, and whose misconduct and violation of several Iron Lord taboos were directly responsible for the disaster) before Lord Felwinter. It provided its records of Eaton's destruction to Felwinter's own Ghost.
List of appearances