An ancient tribe in Africa named the "Moamback". However rare to find a member of this tribe in the United States, it is however, not impossible. Most commonly seen at construction sites or where heavy machinary is used.
Usually the "Moamback" is the person in charge of directing the dump trucks, or the cement trucks. However, not the driver of these trucks, their job is important. They are usually behind the trucks, hollaring "Moamback" to the driver.