The Ultimate Vampire Resource and Directory

Moon shoes were shoes for children fitted with trampoline-like springs. They were billed as "mini-trampolines for your feet".[1] They were part of a merchandising effort by Nickelodeon. [2] [3]
The original moon shoe was introduced in the 1970s and were metal in construction. They were made to fit over the wearer's regular shoes much in the same way as clamp on roller skates. The Nickelodeon product featured closed sides, plastic construction and bungee style springs which can be considered a safety improvement.