Boxy was a Miner Transport Emergency Assistant that served aboard the Tellar sleeper ship that brought Jankom Pog to the Delta Quadrant.
It was built sometime during the pre-Federation era, and she monitored the ship's systems while the crew were in cryo-stasis.
At one point during their long journey, a rock in space slammed into the hull and caused a release in air pressure, that caused a wrench to fall on a cryo-pod and simultaneously awaken Pog, a trainee, who Boxy enlisted to act as an engineer to fix all of the ship's systems that were malfunctioning.
Upon returning to his now malfunctioning cryo-pod, Boxy informed Pog that there wasn't sufficient life support on the ship to sustain the entire crew for the rest of their journey if he were to remain awake. Because of this, Pog decided that it was time for him to leave, as the twenty-nine remaining crewmembers had enough oxygen to survive as long as he wasn't on board. He then left in an escape pod, leaving the crew and Boxy behind. (PRO: "Preludes")