The magic panpipe is an instrument used by Conner in A Grimm Warning to open the Neuschwanstein portal to the Land of Stories. It was stored in Mother Goose's vault in the Lumière des Etoiles Casino in Monte Carlo.
"It says 'G-E-F-C, C-E-G-F'. I'm assuming those are musical notes or maybe it's how you spell a sneeze."
- ↑ TLOS III, ch 11, p. 208