Slime—elemental to life and to eco-horror—is conceptually entangled with many things, some very unsavory. It is an utterly indifferent element, but for millennia in the popular imagination, it has been an elemental intruder, a border-crosser, an agent with bad intentions. Raced, classed, and gendered, slime is unpredictable and uncontainable. Its very elementality is ambivalent. Scholars have grappled usefully with slime as a theoretical concept, but little has appeared linking specific examples of the raced, classed, and gendered slimic imagination with eco-horror. “The Slimic Imagination and Elemental Eco-horror” begins such a discussion, based on specific literary and filmic examples from a range of historical periods, to show that slime is elementally transmorphous, is liminal in many senses, and that it moves freely across the borders of the living and the dead, the solid and the liquid, the dangerous and the necessary, evoking responses as varied as terror and horror, on the one hand, and joy and excitement on the other. Slime appears in variously devious forms in texts from Dickens to Swift, from Brontë to Stevenson, from Roth to Machen, and from Kenneth Branagh to Ridley Scott—never in the same way, but always in ways that demand political engagement.