The character appeared for a very short time somewhere around 1990, after the show's original set and puppets were destroyed in a fire in 1988. Just like Uli Von Bödefeld, she was built by a German puppet workshop, and not the Muppet Workshop.
After her short-lived Sesamstrasse career, she received her own (ALF-like) show, Leonie Löwenherz, that ran from 1991 until 1993. The 44-episode show featured herself, her two lion brothers Lambert and Ludwig, and a small cast of human characters. The series was a co-production of Norddeutscher Rundfunk (NDR) and Hessischer Rundfunk (HR).
Two puppet visually different versions of Leonie existed: the first, slim-faced and slim-bodied puppet that appeared on Sesamstrasse, and the slightly, yet noticeably bigger version, used throughout her own show.