Marx’s humanism haunts the 1844 Economic and Philosophic Manuscripts, which reserves species-being for humans alone, with the capacity for free conscious life activity. This is problematic and seemingly does not represent what we know about the lives of other species. This essay departs from the humanist tradition and argues that Marx’s relational ontology and concept of species-being can be extended to the nonhuman world, bringing Marx up to speed with evolutionary biology and animal studies. Nonhumans possess the capacity to change our material world and live subjective lives, and many times they are the better examples of Marx’s ideal species-being. Enlarging Marx’s concept of species-being provides space for the consideration of nonhuman animals by enlarging the scope of the polis. This situates nonhumans as vital members of political and ecological communities capable of enacting material change while acknowledging the agency of diverse organisms and their dependence on one another in creating their communal lives.