Peg is one of the two titular characters and protagonists of Peg + Cat. She is a young girl who wears a red hat and blue dress. She explains the situation in each episode directly to the "camera", announces when they have "a big problem", and reasons out solutions to math-related problems. During songs, she pulls out a ukulele and plays it. She has a special blue marble hidden under her hat. Her favorite crayon is "Little Bluey".