Emily is a girl mouse and Biff's girlfriend. When Biff first appeared, Emily thought he was cute. She doesn't like it when Biff goes hard on the other mice, and wishes he'd go a little easier on them. In Fitness Crazed, she breaks up with him after seeing Garfield pretending to be tired and coughing after Biff makes him work out. Unlike other mice, Emily likes working out, as she tells Irv in Muscle Mouse.