Depends on the contest, could be an umpire or referee
That depends on what court you're referring to. The person may be a Judge, Magistrate, Justice of The Peace, or Referee.
this person is called a mime.
A person who acts without thinking is usually called "impulsive."
An esthetician is a person that acts something like a dermatologist.
A person who acts may be called an actor or an actress. A person who acts on behalf of another is an agent.
Not surprisingly, a Judge and Jury act as judge and jury.
If it is a rich person who donates money, it is called a philanthropist.
A person who acts on the stage is called an actor or actress, depending on their gender. They perform scripted or improvised roles in plays, films, or other forms of entertainment.
The people that perform the dangerous acts in films are called stunt men or women.
A person who acts as a reserve to a leading actor is called an understudy. They are typically prepared to step in and play the role if the leading actor is unable to perform.
If it is a male, it is called an actor, and (if female) an actress.
the judicial branch