Transhumanist visions appear to aim at invulnerability. We are invited to fight the dragon of death and disease, to shed our old, human bodies, and to live on as invulnerable minds or cyborgs. This paper argues that even if we managed to enhance humans in one of these ways, we would remain highly vulnerable entities given the fundamentally relational and dependent nature of posthuman existence. After discussing the need for minds to be embodied, the issue of disease and death in the infosphere, and problems of psychological, social and axiological vulnerability, I conclude that transhumanist human enhancement would not erase our current vulnerabilities, but instead transform them. Although the struggle against vulnerability is typically human and would probably continue to mark posthumans, we had better recognize that we can never win that fight and that the many dragons that threaten us are part of us. As vulnerable humans and posthumans, we are at once the hero and the dragon.