There was a live-action movie, made in the late 80s/early 90s (possibly made for TV?) It was about a girl/boy would could turn into a blue, muppet-like monster . He/she lands in a magical land at one point in the movie. The protagonist follows an upside down sidewalk for a long time. There is a witch/queen in the movie that derives eternal life from a rose in a glass dome. I forget everything...