How do you make a container to protect a raw egg from cracking when thrown from a 25 foot building ?

i'd try filling the container with pressurized helium. then when they threw it off the building it'd slowly float to the ground.... you could also find some way to orient the egg so it's landing force was absorbed at it's apex and the center of the base (the two points that, if you squeeze as hard as you can, you can't break the egg)

Have a sponge that can wrap the egg completely (a standard sink sponge will be fine) and then wrap it with bubble wrap. Wait, does tape count as part of the materials list? If so, wrap the egg with the sponge and loosely wrap it with tape (masking tape is good). PS Penguins!!!

Have you tried just using bubble wrap and tape to secure it, placed in a container such as a thermos. (It must be able to get out easy, you lose if you break the egg getting it out of the container even if it survies the fall)

open up an empty gallon jug fill it halfway with bubble wrap, put the egg in fill it the rest of the way with bubble wrap and tape the jug shut

Sponge works the best, I've done this before