This progressive disclosure case study explores the medically-related issues of a female infant born with the congenital disorder Sirenomelia, more commonly known as "Mermaid Syndrome." The case starts with a high-risk mother participating in prenatal testing, which reveals a caudal vascular malformation in the fetus, but is not conclusive as to the extent of the deformity. Upon birth, the infant presents with a fusion of the lower extremities and compromised thoracic and abdomino-pelvic viscera. Students are confronted with various medical decisions in each part of the case that could determine the fate of the young girl as a fetus, an infant, and a pre-adolescent. The case can be used in undergraduate allied human health courses that include medical ethics such as introductory biology, human anatomy and physiology, and genetics. It would be suitable for undergraduate pre-professional biology majors, including, for example, pre-medicine, pre-physical therapy, pre-occupational therapy, and pre-physician assistant majors.