In 1935, the graylag goose Martina (1935–?) hatched from an egg in the home of the zoologist Konrad Lorenz (1903–1989). Martina imprinted on Lorenz, slept in his bedroom, mated with the gander Martin, and flew off in 1937. Over the following decades, Konrad Lorenz helped to establish the discipline of ethology, received a share of the 1973 Nobel Prize in Physiology or Medicine, and continued to write about his famous goose Martina. This essay examines the different instantiations of the geese in general, and Martina in particular, in Lorenz's writings aimed at readerships that included prewar zoologists, National Socialist psychologists, and popular audiences from the 1930s to 1980s. By developing an animal with her own biography, Lorenz created an individual whose lived and rhetorical agency made her especially well suited to perform widely divergent aspects of his evolving science. While a significant literature in the history of science has explored the standardization and stabilization of animals in science, I show how Lorenz's creation of a highly protean and increasingly public Martina was co-constitutive of the establishment of his science and public persona.