1. The Egg. The female butterfly lays an egg on a leaf.. 2. Caterpillar. Out of the egg hatches a tiny caterpillar.The caterpillar eats and eats and eats.. 3. The Chrysalis. The caterpillar wraps himself inside a cocoon and stays inside for about 2 weeks.. 4. The Butterfly. Out of the chrysalis comes a beautiful butterfly!.