playact,
roleplay,
act,
play behave in a certain manner; show a certain behavior; conduct or comport oneself; "You should act like an adult"; "Don't behave like a fool"; "What makes her do this way?"; "The dog acts ferocious, but he is really afraid of people"
mime -
imitate (a person or manner), especially for satirical effect; "The actor mimicked the President very accurately"