This is what a Monarch caterpillar looks like when it's ready to morph from a caterpillar into a butterfly. This animal has already been alive for several weeks. As in the Eric Carle book The Very Hungry Caterpillar, it began as a little egg laid on a leaf. The egg was laid by a Monarch butterfly. Then, after the caterpillar hatched from the egg, it got bigger and bigger as it munched on milkweed in its caterpillar form until a few days ago when it climbed up high to hang so that it could turn into a chrysalis. A few weeks after it morphs into a chrysalis, it will emerge in butterfly form. Then, it will be able to lay eggs that will hatch into very tiny Monarch caterpillars.
Have you seen very many Monarch butterflies this summer? I have not. I'm told Monarchs have had a difficult time migrating northward. Maybe you'll come to the library to check in on the chrysalis and borrow some books about butterflies.
Monarch Butterfly Life Cycle