This is an Easter egg variant of the Apparently Impossible Sphere Puzzle. It is interchangeable with the sphere parts to make a "Deviled egg" and an "Avocado" like shape. The bevels were removed from the edges to give a smooth looking egg when assembled.

Since there are no flat surfaces to use as supports this is a little harder to align and put together when compared to the cube. Pinching the pieces together across the flat inside faces helps maintain an alignment so the pieces can be moved into place.

UPDATE: 5/6/2018 An assembly helper base can be found here: https://www.thingiverse.com/thing:2890931

Print two of each of the pieces (they are mirror images) or print the 4 piece assembly directly.

Video of the parts going together can be found here: https://www.youtube.com/watch?v=yMmbbx7IR-s