Egg
Female butterflies lay their eggs on or near the host plants of the caterpillar. Monarch caterpillars feed on milkweed plants so you will commonly see eggs laid on the leaves or stems. Circular in form, they are most times milky white in color.
Caterpillar
After emerging from the egg, the caterpillar is fairly small. As they continue to feed on their host plants they shed their outer skin, about five different times, so that they can continue to grow in size. Color, shape and distinctive markings become more vibrant as they continue to molt. Some “eye” markings or vibrant colors are intentional in order to detract predators, like the vibrant striping on the Monarch. The toxins in the "milk" of the milkweed plant make monarch caterpillars poisonous to eat.
Chrysalis
After the caterpillar has gorged itself and grown to its full size it will attach to the host plant and shed for the last time. This last shed is the initial formation of the chrysalis. After it has fully formed, the chrysalis protects the insect during its final transformation as the fleshy tissue breaks down and the legs, body, antenna and wings are formed. With a Monarch chrysalis, it starts out a vibrant green color and right before the butterfly emerges, the casing becomes very transparent to the point you can see the bright orange and black markings of the butterfly underneath.
Butterfly
Once emerged, the butterfly is at its most fragile. It will hang from the shell of the chrysalis for as the wings unfurl and become stronger and rigid. Then the butterfly takes flight, looking for nectar from the host plants of the butterfly which might be different from the host plant of the caterpillar. They also look for puddling areas in order to take in nutrients and salt as well as sunning areas. Some butterflies, like the monarch, migrate south for the winter in large flocks and return again each spring.