In an Instagram post, Gower said that his team "drew inspiration from fungal and mushroom reference" along with artwork from the original video game as the inspiration behind the design. He shared a photo of an intricately painted fungus prosthetic (which he credits to Victoria Holt), noting that the designers mocked up "thousands of infected appliances" throughout the show's first season.
When it came to the Runners, Gower told Entertainment Weekly that the "raised veins" seen on the recently bitten are meant to show how the infection makes its way from the bite mark to the brain. "We had to show some kind of travel in the vein network coming up through the body," he told the outlet. "We looked at lots of different organic shapes for veins. We looked at things like worm larvae burrowing under the skin. We looked at jellyfish, the scars that you get in these random organic patterns, and we also looked at leaf miners, which you can see sometimes on leaves and plants. It's a parasite, a termite, which burrows under the skin of the leaf and creates all these swirls."
