Don’t even think about calling HBO’s “The Last of Us” a zombie show. Eben Bolter, the cinematographer who shot four episodes of the video game adaptation’s 10-episode first season, recently told The Credits that referring to the series as a zombie show or using the word zombie to refer to the undead characters was strictly not allowed on set.

“We weren’t allowed to say the Z word on set,” Bolter said. “It was like a banned word. They were the Infected. We weren’t a zombie show. Of course, there’s tension building and jump scares, but the show’s really about our characters; The Infected are an obstacle they have to deal with.”

“There’s a lot of things The Last of Us is not,” the cinematographer said earlier in the chat. “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.”

In the world of “The Last of Us,” the human population has been destroyed by a brain-eating fungus. While the undead act similar to zombies, they have a completely different look due to the fungus transforming their bodies. The undead are referred to as “clickers” and “bloaters” depending on what stage of the infection they are in. A bloater’s body is completely covered in fungus, which “The Last of Us” team achieved in Episode 5 by using practical prosthetic effects on a 6’6” U.K. stuntman.

“We had a whole copy of his body that we modeled the bloater prosthetics over in modeling clay,” the show’s prosthetics designer Barrie Gower recently told Variety. “We cast it out of a foam rubber and foam latex, which is very lightweight. It’s almost like an upholstery foam, a very spongy sort of material. That was all molded and cast in separate sections: top half, head, arms, legs. We had a team who fabricated all these parts together. We had a zipper up the back and around the waist that we could zip them together. He had all these pendulous folds of fungus which hid zippers and poppers.”

New episodes of “The Last of Us” air Sunday nights at 9pm ET on HBO.