The pupa-stage is the third phase in the life-cycle of a butterfly. It is in this phase that a pupa gets transformed into a butterfly. A butterfly pupa is commonly known as a chrysalis, and it is often found on the underside of a leaf, or in other concealed locations. Even though the pupa seems lifeless on the surface, amazing changes in fact take place inside the pupal skin. During this stage, the pupa is more vulnerable to predators, as it cannot move.
Hence, the pupae camouflage themselves with the colour and texture of their surroundings to prevent detection by enemies.
The span of time that a pupa spends in this stage varies from weeks to months, depending upon its species. There are other types of pupae which are very bright in colour. Most of these pupae are usually poisonous.