This egg can be found hover off the floor of the Cave. It sparkles a bit as you look at it closer.
The Matta is an all-seeing magic carpet that patrols the depths of Fairy World. With its eye, it reports all evil and wrongdoing to the Fairies who are responsible from purging Fairy World from darkness. If it weren't for the Matta, darkness might spread in Fairy World.
The Matta is an important part of this balance of the realms.