[Editor’s Note: The following interview contains spoilers for “Guillermo Del Toro’s Cabinet of Curiosities” Episode 7, “The Viewing.”]

If a fake exploding head is going to look believable, you need to fill it up first. Just ask Dennis Berardi, the visual effects supervisor on “Guillermo del Toro’s Cabinet of Curiosities.”

“We packed it with bits of lookalike meat and some fleshy bits. It was all stuff that wasn’t real organic. It needed to keep and fit the molds,” Berardi said.

It wasn’t the only part of this process that needed some practical glop in order to bring something terrifying to life. All of that work was in service of “The Viewing,” the Panos Cosmatos-directed episode of the Netflix horror anthology. In it, a handful of strangers are summoned by a wealthy eccentric (Peter Weller) to witness a strange addition to his collection. After a night of rare booze and Space Cocaine, the group gathers around...