Flossie is Herry Monster's baby sister. She was featured in a number of books, and had starring roles in A Baby Sister for Herry and It's No Fun to Be Sick! Although she was never introduced as a puppet character on Sesame Street, Herry mentions her in a scene with Kim.

Book appearances

• A Baby Sister for Herry (1984)
• Big Bird Goes to the Doctor (1986)
• A Sitter for Baby Monster (1987)
• Oh, I Am So Embarrassed! (1988)
• It's No Fun to Be Sick! (1989)
• Halloween Party (1991)
• Sleep Tight! (1991)
• Too Little! (1992)