Netflix’s Jenna Ortega-led second season of Wednesday, while released in an annoyingly incremental fashion, has given fans tons of thrills and fast-favorite moments, including the extremely hyped arrival of one Mother Monster, Lady Gaga. Among the more astonishing moments in the season so far, however, are the visual effects and prosthetic designs—including a zombie and putting Christopher Lloyd’s head in a jar. The show’s visual effects team lifted the veil on how they pulled it off in an interview with The Hollywood Reporter, with Wednesday‘s prosthetic designer Tristan Versluis saying that one of the biggest challenges of the season was bringing to life zombie Slurp (Owen Painter). Versluis and crew had to make sure Slurp was believable as a zombie, but also playable by an actor in makeup instead of a purely CGI creature. “There are many different types of zombies, and we were trying to find that unique look that was both enhanced, and was part of the world of Wednesday and Nevermore and the showrunners’ visions, and we landed on it with guidance from Tim [Burton] and the sketches and edits to some of our designs,” Versluis told The Hollywood Reporter. After Painter was confirmed to play Slurp, Versluis explains how the VFX team took their design and applied it to his face and body stage by stage. Wednesday visual effects supervisor Tim Turnbull told The Hollywood Reporter that early episodes with Slurp necessitated more CG elements than later episodes to sell his grotesque, undead nature. “When he first comes out of the ground, he’s in rough shape, so that’s where the CG really came in, that’s where biggest enhancements were,” Turnbull said. “By episode five, we’re doing very little [with CG]: His jaw still distends quite largely in those episodes and he has a giraffe tongue, but the hole in his head is gone and his nose has grown back. So most of our work was in episode one, and it phases out to be more and more practical as we went deeper into the episodes.” Much of this has to do with both narrative reasons, where Slurp regenerates after consuming human brains, and to achieve a “classic horror zombie vibe” with its prosthetic effects throughout the show, while still maintaining a consistent appearance rather than having Slurp look like an entirely different person throughout the series. “Prosthetics is about enhancing and adding to the acting—we can only add—so we added enough to start stripping back through the stages. The prosthetics got thinner, and we started to bring out more cheekbones of Owen and some of his facial features until we feel like he’s coming back into it.” Versluis said. “So hopefully there are no jumps where you suddenly say, ‘Oh, who’s this?’ We feel familiar at that point.” While the crew prided themselves on maintaining an old school prosthetic touch to pulling off Slurp, Wednesday‘s implementation of Christopher Lloyd’s Professor Olof proved to be an even bigger challenge, as his head-in-a-jar form forced the team back to the drawing board. In the past, Turnbull explained how a VFX team would’ve likely have made Lloyd record his lines in front of a blue screen and then composited the shots together, but doing so would’ve made it “look like a CG head in a jar”—something the team did not want to do on Wednesday. Instead, the team worked with Eyeline Studios to make a 4D volumetric capture of Lloyd to achieve the effect at a high resolution of 60 frames per second. “So what’s in the jar is an actual direct translation of his performance, which I think is what gives it its reality. We didn’t change his performance except adjusting his eyelines a bit,” Turnbull said. “What you see there is Christopher Lloyd. The layer of CG that we put on it is really only there to support it, rather than take it over.” And there you have it: all the practical and technological magic that Wednesday‘s VFX crew has pulled off to make this season’s most intricate effects. “A lot of technology went into that, a lot of smart people working on a difficult problem and an enormous amount of data to process to come up with something that looks pretty simple,” Turnbull said. “That’s the beauty of that.” Season two of Wednesday is streaming on Netflix.