Mona Monster is Telly's older sister who has a very vivid imagination. She appeared on Sesame Street briefly during season 13. She also appeared with other Sesame Muppets in the wedding finale of The Muppets Take Manhattan. Mona Monster also appeared in the second edition of Sesame Street Live, Big Bird's Super Spectacular Totally Amateur Show. She is not named in the program; instead she is referred to as "Turquoise Monster."