Mickey was born as the eldest son of Finbar O'Leary, a traveler from Ireland. As the eldest of many brothers, Mickey helped raise most of his family teaching them all from a young age the tricks he had learned to survive on the road. As he's Da traveled across Europe in search of a new wife every few years Mickey became a skilled con artist and would make money to feed his family by scamming unsuspecting tourists. However, he never took more than he needed to survive, any excess money he would use to treat his younger siblings. At the time of the outbreak the O'Leary family was travelling through Chenarus and when the border closed they found themselves trapped in the country.