Mike (portrayed by Teddy Sears) is a male Caucasian Active. In "Needs", he slept in the same pod room as Echo, Victor, Sierra and November. Like them, he supposedly awoke with his original personality but without his memories, and assumed they had been abducted by aliens.
Mike tried to blend in with the other Actives, but was too nervous to speak like them. He was hauled away for wiping before he could try to escape.
It is likely that the purpose of having Mike be with them and be caught was to give Echo, Victor, Sierra, and November an incentive to escape. As such, it is dubious that the paranoid personality he displayed was his original personality.