Mona Monster

From Muppet Wiki

Mona Monster is Telly's older sister. She has a very vivid imagination and briefly appeared on Sesame Street in the early 1980s.

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."

The puppet used for Mona Monster was reused several times, including as Frieda and Juliet. In 1991, the puppet was used, and popularized, as Ingrid and has been connected to that character ever since. Mona has not reappeared.