A Plastic Egg is great for the Egg Bag routine. It is better than a wooden one, being lightweight. A wooden egg causes the bag to sag and gives away its presence.
The Plastic Egg is perfect for productions where a large quantity of something is desired.
Since the egg is itself a rather comic thing, the production of a large number of them is sure to raise a good crop of laughs.
It is also possible to make a Stodare Egg out of a Plastic Egg for the Silk to Egg trick. It can be done by tracing a penny on one side, then with an Exacto knife cut out a hole for the reception of the silk. Sand any roughness away and it's ready.
A Plastic Egg is just that, made of plastic and hollow.