The Reality of Parasitic Zombie Fungi From "The Last of Us"

By Ina Kim

Watching grotesque humans covered in mushrooms run in ruined cities would certainly not please anyone to eat mushrooms now, because The Last of Us has the exact gruesome image of these human fungus-infected zombies. 

Cordyceps. It’s a type of fungus that infects insects using spores in real life, making them into “zombies.” In June 2013, an apocalyptic video game titled The Last of Us was released. The video game was later produced into a television series in January 2023, leaving a profound global impact. The show mainly focuses on infected zombies that were heavily inspired by the real-life fungus Cordyceps. But how closely does Cordyceps relate to the infected ones in The Last of Us? 

In real life, Cordyceps spread from the fungal spores that they hold. National Emerging Special Pathogens Training & Education Center (NETEC), an educational company, has said that fungal spores could be inhaled and “...tend to spread in two ways: vertical transmission from mothers to their offspring and horizontal transmission through spores in the environment.” 

What about the fungal zombies from The Last of Us? A bite, inhaling spores, or even tendrils that emerge from the zombies’ mouths. 

Cordyceps is a very hard fungus to get rid of, as no vaccine has been created currently. In The Last of Us, the only way to get rid of these zombies is to bomb the infected areas. But the show didn’t end right there, of course, because bombing only spawned more revolting of those fungus-infected zombies. 

Now, as the fungus continues to grow throughout its host, the Cordyceps starts to chew through its exoskeleton and the fungus releases into the host fast. Insects have something called “chitin.” Chitin is the key component of an insect’s ecosystem, being used as protection for the frail bodies. 

National Geographic says that an infected ant won’t behave normally like other ants and they will “...descend to a vantage point about 10 inches off the ground, sink its jaws into a leaf vein on the north side of a plant, and wait for death.” 

Although the real-life fungus takes time to develop, The Last of Us features their beginning stage zombies, which are the Runners—the weak and clumsy, yet still quick with their feet. Infected hosts become Runners after two days, or possibly even less. Runners still look human-like, but don’t you run after one that looks like someone you loved. 

The good news for us: Cordyceps cannot infect a human because of our complex immune systems and body temperatures. Fungi can’t handle high heat, being killed off immediately. 

Ironically, while The Last of Us shows how terrible the usage of Cordyceps could be, Cordyceps in the real world can be useful for pesticides to target insects that could be unsafe to crops and boost energy and strength in humans.  

While everyone can sit back and continue to watch the grim scenes of fungi-like zombies scamper after victims and click through their mouths, we can thank our complex yet exceptional immune systems for not letting any sort of fungal virus into our bodies. Having the real-life Cordyceps be inspired by the infection in the successful television show The Last of Us truly left a few the big question: what if our body temperatures aren't hot enough?