camp follower 
noun
1A civilian who works in or is attached to a military camp.Each camp had chaplains, cooks, camp followers, singers, and verse writers....
- Since most armies lived off the land, and this often limited the size of the army, the force that hauled along the fewest camp followers had a substantial military advantage.
- As the theatre of war moved south, so did the smallpox, primarily affecting civilians, camp followers, and irregular troops in both armies.
1.1A person who is nominally attached to a group but does not make a substantial contribution to its activities: cynical opportunists and camp followers...
- The mass goes well, and our camp followers inform us that we sounded well in the cathedral.
- One of the Scotland team's camp followers, in between filing reports on Scotland's opening match against Japan, managed to find time to enjoy the debilitating night life.
- The initial reaction from governing elites and their media camp followers was disbelief.