This caterpillar is about to change into a chrysalis. The change will be so great — and so sudden— you'll think a new creature has appeared before your eyes.

What to watch for: The caterpillar stops eating and climbs to a safe place. It hangs upside down in the shape of a "J." Within 24 hours the larva will pupate.

It only takes a few minutes for a caterpillar to turn into a chrysalis. You can wait all day, walk away for a minute, and return to find a chrysalis already there.

What to watch for: The front tentacles wilt about 30 minutes before the larva pupates.

Time-lapse Images
These images were taken within 7 minutes. What happens to the eyes, mouth, face, and legs of the larva? Watch for the gold necklace.

The Chrysalis
You can already see parts of a butterfly when the chrysalis is only a few minutes old.

"By the time the larva pupates, the major changes to the adult form have already begun," says Dr. Karen Oberhauser.

Time-lapse Images
View the metamorphosis from a different perspective. Watch to see where the skin splits.

How does the chrysalis get the air it needs?
Move mouse back and forth on photo. The holes on the side of the chrysalis are called "spiracles." "The air goes into these holes and through a whole series of tubes in the body called trachea. The trachea carry oxygen throughout the monarch's body," says Dr. Oberhauser.

Did You Know?

• The chrysalis is not a cocoon. A moth forms a cocoon. A butterfly forms a chrysalis.

• The chrysalis is also called the pupa. The process of changing from larva to chrysalis is pupation.

• The green coloring of the monarch pupa is the skin of the monarch during this life stage.

• The final molt (shedding skin) of the monarch larva results in the chrysalis. "The chrysalis is not so much something the monarch makes as something it turns into," says Dr. Oberhauser.