Agitator

Ag·i·ta·tor

Agitator

n.
  1. One who agitates; one who stirs up or excites others; as, political reformers and agitators.
  2. One of a body of men appointed by the army, in Cromwell's time, to look after their interests; -- called also adjutators. (Eng. Hist.)
  3. An implement for shaking or mixing.