The person that tells the pilot where to go, what to do when they get there and no, they can't have a break. They also swear a lot when the pilot grounds his aircraft for a stupid reason. The goal of this is to prevent flights from arriving in time for passengers to make connecting flights.
They also cancel flights, predict the future, turn water into wine and walk on water.
Don't sass me boy! I'm the flight dispatcher! Fix your skirt and get back in the plane!