Character Circle is a character matching warmup.
All players stand in a circle. One person then steps into the middle and looks at one of the people in the circle. That person must start delivering a line of dialogue as a character. The person in the middle then will mimic that character, finishing the line. The person in the middle then looks to the next person in the circle, and play continues until every person around the circle has started a character. Then the person in the middle returns to the circle and a new person steps in.