This is a real chicken egg that has been carefully hollowed out, sterilized, and decorated. It is stitched with high-quality embroidery thread and finished with an eggshell panel to hide the back of the stitching.
Edit to say: Wow, a Daily Deviation? Really? I feel so honored! Thanks to ChimeraDragonfang for the nomination, to ^Talty for the feature, and to all of you for all the favorites!
A common question in the comments was, "How did you do that?" The answer is, "A very tiny drill bit and a lot of patience."