Danny and Sammy Rex are Erec's twin brother and sister.During the first book Danny and Sammy went missing.In the second book Erec uses the Seeing Eyeglasses to not see,but to hear them giggling and calling themselves fat.Then Erec finds them and returns them to Upper Earth. it is later revealed that they are the king and queen of clowns by Mrs. Smith, learning they are called Derby and Shalimar.