What is a good insulator for an egg?

Question

We are putting an egg in a small box and dropping it off a buliding with a rubber band around it.

What would insulate it so it doesn't crack?

No:

Packing Materials (packing peanuts, etc.)

Plastic

Bread

Marshmallows

It can be a liquid, but the box is cardboard.

If I think of any others that aren't allowed, I'll post.

A good example would be Twinkies!

Answer 1

Soak the egg in vinegar.   . That will turn the egg shell rubbery.   Then, encase it in gelatin.     Drop it off the building, retrieve the egg, soak it in water and the shell will return to normal.

You didn't mention anything about changing the composition of the egg.    That, or hard boil it first.