Metamorphosis: biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Transition: the process or a period of changing from one state or condition to another. Transmigration: the movement of a soul into another body after death. Extrapolation: the action of estimating or concluding something by assuming that existing trends will continue or a current method will remain applicable.