This new volume of Current Topics in Developmental Biology covers recent progresses in our understanding of animal metamorphosis. Over a dozen of leading experts reviews studies ranging from morphological, molecular to genetic analyses of metamorphosis in a broad spectrum of animals, including insects, fish. Topics include molecular evolution in metamorphosis, the synthesis and function of hormones in regulating metamorphic timing and rate, regulation and function of nuclear hormone receptors, neuroendocrine control of metamorphosis, tissue specific metamorphic events such as autophagy and stem cell development, and applications of genome-wide analysis technologies for studying metamorphosis.