Do we need to worry about a fungus that ultimately turns humans into zombies with parasitic tendrils coming out of their mouths, ready to attack?

That’s the concept behind the world-destroying pandemic in The Last of Us, a new HBO series based on a video game that’s known for mixing the zombie apocalypse genre with heart and humanity.

In the series, survivors struggle to endure a world where cordyceps, a type of fungi that typically infects ants or spiders, is able to jump to the human population due to climate change. Parasitic Cordyceps take over the host body by filling its cavity with spores.

In the TV show, humans are taken over by the fungi and turned into zombie-like creatures that chase survivors in order to infect them through a bite.

According to James Scott, a professor at the University of Toronto who specializes in biological hazards and microfungi, it may not just be the stuff of science fiction.

“We already have a lot of diseases of humans caused by fungi. But the fortunate thing is, there are lots of fungi on the planet, millions of different kinds, and there’s really only a handful that cause serious diseases of people,†Scott told CTV’s Your Morning on Friday, explaining that a pandemic fuelled by cordyceps is actually possible.

For the most part, he added, if a human is infected by a fungus, it’s difficult for them to transmit it to another human.

But that could change, Scott said. “The more we uncover remnants of lost rainforest in all sorts of far-flung rainforests, there is a possibility to encounter some of these things… that could then jump into the human population,†he said.

Watch the full interview above to learn more and about how fungal and bacterial infections differ.