Twelve

Service Robot Twelve was a machine used in snowglobe 7 in 2099. It was part of the rubble scavenged from the accident that occurred in one of the tunnels. The Doctor repaired it to the surprise of the engineers and used it to help him find the exact location of the accident. Somehow, it gained human emotions that made it afraid and agitated as it approached closer to the accident area. (NSA, Snowglobe 7)