Here's an egg with a fun surprise, a spinning platform inside. Just twist the flower knob on and watch a flower and butterfly spin. Or replace it with your own item (approximate maximum item size: 45 mm x 30 mm high) for a fun, personalized gift. See it in action here: https://youtu.be/0kbkO8Ykfzs
Assembly tips - insert the gear and shaft. The gear should be near the front of the egg. Line up the indentations on the gear plate with the tabs on the side of the egg. The gears should face down (into the egg). Place the flower knob on the axle and the small circle on the other side of the shaft (near the hinge).
The flower handle will need a touch of superglue so it doesn't slip while spinning. The pin of the hinge is small piece of 1.75 mm filament. The daffodil can be attached to the base either by using a piece of 1.75 mm filament or with super glue.
This project contains remixes of: https://www.thingiverse.com/thing:2206981 (e3dOnline) and https://www.thingiverse.com/thing:1655124 (kresty)
The spining-egg.stl contains all the objects in one stl file. The spinning_egg.zip contains each of the objects in its own stl file.
This object was made in Tinkercad. https://www.tinkercad.com/things/dapSSycFdI8