Representing the psychological age of a six-year-old, Ieniemienie is the oldest of the group. She is very clever and smart-alecky, and sometimes she tends to be a little bossy. Her best friend is Tommie. Being the smallest person on Sesamstraat, she often hangs out with Pino. Ienie is famous for her giggle, as well as her signature movements like scrunching her nose when she's angry or frustrated or raising her shoulders when she's confused.
Ieniemienie was introduced in 1980 as Ienie Meinie. She started out as a mouse who lived in a hole and was often searching for cheese. Through the years, when female emancipation wasn't as much as an issue on the street, her personality became more childlike and girlish.
The puppet has been refurbished a few times, but without drastic changes; except for the 1996 anniversary special, in which Ieniemienie's legs were shown for the first time, during a stiltwalking scene.