WordNet (r) 3.0 (2006):

straw boss
    n 1: a member of a work gang who supervises the other workers
         [syn: straw boss, assistant foreman]

Moby Thesaurus II by Grady Ward, 1.0:

30 Moby Thesaurus words for "straw boss":
   Big Brother, auditor, boatswain, boss, chief, comptroller,
   controller, floor manager, floorman, floorwalker, foreman, gaffer,
   ganger, head, headman, inspector, monitor, noncommissioned officer,
   overman, overseer, proctor, sirdar, slave driver, subforeman,
   super, superintendent, supervisor, surveyor, taskmaster, visitor