If you don't have plastic eggs, you can use real eggs (either raw or hard boiled eggs) in this. I would just be careful about using raw eggs because you don't want to press down too hard and crush the egg in your hand. What's great if you use hard boiled eggs is that this is a dye-free way to decorate Easter eggs. So, when you want to eat these, you don't have to worry about eating food dyes (which some people are concerned about). Just crack the shell on these and eat away. Although, if you're not concerned about food dye, you actually could dye eggs, let them dry, and then add washi tape on top of the dyed egg to give them a little extra pizzazz. If you want to use real eggs and keep these for a long time, you'll want to use blown out eggs. If you do that, you'll just want to make sure the eggs are completely dried out before you start crafting with them. You're going to cover the holes that you use to blow out the eggs, so you want to make sure there's nothing wet inside that can start to smell after a while.