Justin

Justin is Mrs. MacGrady's grandson. He only appeared in the book Arthur and the Pen-Pal Playoff.

Justin is a 3rd grader on the other side of the state from where Arthur lives. He likes playing basketball, and occasionally comes to Elwood City to visit his grandma. In the book, Mrs. MacGrady arranged for Arthur and Justin to be pen-pals, that way they could meet each other.