Here is an Easter Egg shell - two parts top and bottom.

Can be found here also:
https://www.matterhackers.com/store/digital-designs/easter-egg

Printed with MatterHackers PET+ FIlament and they turned out really well. https://www.matterhackers.com/store/3d-printer-filament PLA should work ok also.

If needed - scale the bottom or the top half 1 or 2% to compensate for individual Printer tolerances.