Name a creature that lives in a cocoon for part of its life cycle.

The life cycle of a butterfly is a key example of metamorphosis that includes a stage where it lives in a cocoon, specifically during its pupal stage. In this stage, the caterpillar undergoes significant transformation, and while it transitions into a butterfly, it is actually the pupal stage that is encased in a protective covering known as a chrysalis, which is often referred to loosely as a cocoon.

The caterpillar is the larval stage of the butterfly and does not itself live in a cocoon; rather, it transforms into the pupa stage where it becomes encased. Therefore, while the caterpillar ultimately gives rise to the adult form, it is not accurate to say that it lives in a cocoon during part of its life cycle, as it is outside of such a protective structure before undergoing metamorphosis.

On the other hand, moths also experience this transformational process and live in cocoons during their pupal stage. Thus both butterflies and moths belong to the group of insects that go through a metamorphosis stage where they are encased, but the specific reference needs to be made to the correct stage of development and the form that is physically encapsulated for transformation.