Imaginal is the last stage after which the caterpillar transforms into a butterfly also known as the pupa or chrysalis stage. The whole metamorphosis of the butterfly is an almost magical process rarely found elsewhere, in the world of living species. For one, the different forms in the metamorphosis are distinct from one another, so distinct that while in a particular stage, it would be difficult to imagine how the next form would appear for those viewing it from the outside.