According to a cinematographer working on HBO’s The Last of Us, the word “zombie” was banned from the set of the TV series. Eben Bolter, who is responsible in part for the show’s absolutely stunning visual imagery, said in an interview that the word “zombie” was banned on set because The Last of Us universe doesn’t have zombies–the humanoid enemies are instead known as Infected.

“It’s not a cliché zombie movie, it’s not Hollywood backlit where everyone’s close-up is perfect. It’s a world of organic cinematic naturalism, and that’s something I could just feel,” Bolter told The Credits. “We weren’t allowed to say the ‘Z word’ on set. It was like a banned word. They were the Infected. We weren’t a zombie show.”

The “Infected” in The Last of Us are humans who have been infected by a Cordyceps fungal disease. The fungus infects the brain of its host and gives them traits and characteristics associated with the traditional “zombie.”

Scientists have observed that Cordyceps can, in real life, infect and control ants and spiders through the brain, but that isn’t what happens to humans. In fact, people have been eating Cordyceps for thousands of years and enjoying their medicinal benefits.

Northeastern University associate professor Rebeca Rosengaus told BuzzFeed News that Cordyceps cannot, in their current form, hijack a human brain and control it like what happens in The Last of Us video game and TV series. Whether or not the fungus could evolve over time and adapt to warming temperatures and kill us all remains to be seen.

The Last of Us features everyday Infected as well as more frightening variants known as Clickers and Bloaters. The newest episode of the series introduced a Bloater, and it was a sight to behold. New episodes of HBO’s The Last of Us air Sunday nights.