Butterflies have 4 lifecycle stages.  The pictures illustrate a monarch's lifecycle.

1. Egg 
The adult butterfly lays eggs on larval plants. Each butterfly specie lays eggs in a different place. Monarch often lay the eggs underneath the leaves of a milkweed plant. 
(Picture to come - monarch eggs are small, green, and round)

2. Caterpillar
Once the caterpillar hatches, it is very small. It begins to eat. Some eat the egg shell and others eat the larval plant. The caterpillar keeps eating and growing. As caterpillars grow, they may stop eating and stay still until they shed their skin.  When they are finally big enough, the caterpillar stops eating and finds a place to hang from to form a chrysalis. 

The monarch caterpillar hangs in a J shape. This caterpillar will soon be ready to hang and form its chrysalis.

   

3. Chrysalis
Butterflies do not make cocoons! They form a chrysalis.  

The Monarch chrysalis is green until a couple days before the butterfly hatches when it turns dark and you can start to see the wings. 

4. Butterfly
The butterfly has to push its way out of the chrysalis. Its wings are wrinkled and it abdomen is fat. It stretches its wings out by pumping fluid stored in the abdomen into the wings. The butterfly has to hang still for awhile and let its wings dry. Then it opens and closes its wings. Finally it starts to fly around. 

The butterfly looks for nectar. When it finds some, it sticks its tongue (proboscis) in the nectar flowers and eats. It has to find a mate before it can lay eggs to start the cycle all over again.