Animalism is the view that we are biological beings, i.e., organisms or animals, and have biological persistence conditions. Personal identity, properly understood, is biological identity. In this chapter, I discuss this core animalist tenet, arguing for three claims – (i) the Harmless Claim: animalism has not yet sufficiently explicated its key notion of biological identity; (ii) the Not-so-Harmless Claim: a large part of what animalists do say about biological identity is in tension with what biologists and philosophers of biology say about biological identity; (iii) the Radical Claim: animalism cannot provide a convincing account of personal identity so long as the notion of biological identity employed is based on the metaphysical assumption that organisms are substances or things composed of (smaller) things. I argue that only processual animalism which recognises organisms as processes can deliver a truly convincing account of biological and, hence, personal identity, thus overcoming a characteristic dilemma faced by psychological accounts of personal identity, rather than repeating it.