Avian eggs are remarkably varied in their color, pattern, shape, size and ultrastructure. What evolutionary forces have affected their appearance and form? Using a multidisciplinary approach, I will explore the phenotypic diversity of avian eggs from functional and mechanistic perspectives, focusing on cuckoo egg mimicry, speckled songbird eggs, shorebird egg camouflage and nano-scale shell structure. I will highlight the power of using tools from diverse disciplines, including computer vision, mechanical engineering and comparative genomics, to ask fundamental questions about avian behavior and life history at the egg stage.