This text outlines the significance of the animal for thinkers including Friedrich Nietzsche, Martin Heidegger, Jacques Derrida, Gilles Deleuze, Donna Haraway, Peter Singer, Giorgio Agamben and Rosi Braidotti. There are chapters on Theorising Human and Animal; Animals as Humans; Animal Ontology; Animal Life; Animal Ethics; and Future Directions in Animal Theory.