Is the Cordyceps fungus from The Last of US real?

Yes, Cordyceps is a real fungus naturally occurring in nature. However, unlike its portrayal in the The Last of Us videogames and TV show adaptation by HBO it can not infect humans and is in fact often used in medicinal supplements and even eaten as food. The Cordyceps fungus does infect insects in real life, with ants and caterpillars being the most common hosts. The Cordyceps takes control of the motor functions of the host and eats the host from the inside.