This essay argues that Octavia Butler’s Fledgling traces, in the transformation of the protagonist Shori from mere zoē into bíos, the evolution of a posthumanist condition where vampires coevolve with humans. This occurs in three stages before climaxing in a posthumanist corporeality that involves a multispecies biological citizenship. Shori’s biovalue and biological citizenship is at once corporeal and moral. Biovalue in Butler’s posthumanist vision, I conclude, inheres in the moral enhancement of Shori and is the result of her multispecies citizenship.