Kog was created by Doctor Ovi Kintobor in a time when the Metropolis Zone was still all fields. Kintobor was so thoughtful that he shut Kog down every night to rest. However, when a lab accident transformed Kintobor into Doctor Ivo Robotnik, he forgot about Kog, who was left abandoned.
The inactive Kog was somehow brought to Citadel Robotnik in the Metropolis Zone. After the building was destroyed, some workers attempted to bulldoze the area. During a Badnik attack, however, a bolt of electricity hit an exposed wire in the wreckage, re-activating Kog. When Kog emerged, the workers were initially afraid and wished to destroy it, although Tails realised that Kog was not dangerous. Kog was eventually given a polish and an overhaul, and given a job teaching people about the history of Mobius before Robotnik's rise to power. It was generally agreed that he was more interesting than any history lesson.
Kog resembles a silver humanoid robot with green joints and red eyes, as well as a red light on top of his head. He has tracks on the soles of his feet, and shortly after being awakened the green panel on his chest displayed a moving graph (resembling an electrocardiography reading).
- Kog bears strong resemblance to the Iron Giant from the film Iron Giant.