In most animals, the drive to breed and produce offspring is strong. However, most males live their whole lives without having the chance to breed. The events leading up to mating can be very dangerous and also very costly to an individual. Some males have evolved elaborate structures, or weapons, as a result. The structures do help males in both combative situations and with attracting females, but ironically, the structures themselves come with certain costs. This flipped case study provides students with the opportunity to not only see how animal structures and functions are linked, but also to see how certain animal structures are needed and costly. There are videos that students are expected to view before the case. The case was initially designed for a second semester college general biology class for majors. However, it can also be used in non-major biology classes. Students should have some background knowledge of natural selection, specifically sexual selection as well as energetic demands of certain structures.