The butterfly chrysalis is the stage where metamorphosis occurs. Metamorphosis is a process through which a larval form becomes a winged adult.
The chrysalis is the pupa form of an insect. The word "pupae" comes from a Greek word meaning 'gold'. Some butterfly pupae cases have a gold or metallic sheen. Some of these cases have gold or metallic dots.
They come in all shapes and sizes. Each species looks different. Some may be green or brown. The color helps to camouflage the case.
Butterflies do not make cocoons. Moths make cocoons.