Shape-shifting representation is common in practice but largely shunned in theoretical and empirical analysis. This article resurrects, defines, and explores shape-shifting and closely linked concepts and practices such as shape-retaining. It generates new concepts of representative positioning and patterning in order to aid our understanding, and makes the case for placing this critical phenomenon front and center in the analysis of political representation. It examines crucial empirical and normative implications for our understanding of representation, including the argument that shape-shifting representation is not intrinsically undesirable. Developing the theory of shape-shifting representation can prompt a new level of analytical purchase on the challenge of explaining and evaluating representation's vitality and complexity.