Other-than-human persons and the role they play in transforming social, economic, and ideological material realities is an area of expanding interest in archaeology. Although the Anishinaabeg were an early and vital focus of cultural anthropological studies on nonhumans given their significant relationships with other-than-human persons, known to them as manitou, emerging archaeologies advancing this topic are not largely centered on ancestral Anishinaabeg sites and artifacts. This article analyzes a set of nonvessel ceramic artifacts from Late Woodland archaeological sites in the Inland Waterway in northern Michigan, which are interpreted to be ceramic renderings of manitou. I argue that these were manitou-in-clay, vibrant relational entities that are brought into being for and through use in ceremonial perspective practices related to Mishipishu—a complexly powerful, seductive, and dangerous nonhuman being known as the head of all water spirits. I contextualize the making and breaking of Mishipishu manitou-in-clay as acts of petition by hunter-fishers who had been seduced by this manitou in dreams, as they headed out on necessary but high-risk early-spring resource harvesting in the inland lakes of the Inland Waterway. This case advances insights into how relationships with other-than-human persons were coproductive of the world in the northern Great Lakes region during the Late Woodland period.