While it might sound extreme, using real meat for stop motion is an actual technique used by stop motion legend Jan Svankmajer.
In a 2024 interview with Daily Dead, Robert Morgan spoke in detail about integrating the live-action and animation elements during the shoot: "It was a five-week shoot, and we divided the stop-motion stuff into two halves. The first half was as the live-action unit was shooting all of the live-action stuff, the scenes where there is stop-motion animation elements interacting directly with live action, of which there are a few, were shot. Basically, we would shoot the live-action plate with Aisling Franciosi, for example. Then we had a replica set that was the same measurements and everything.
It's all very technical, but I'll give you an example. The scene where the puppet walks into the bedroom, when she's in bed, we had a set that Aisling was in that we shot. Then we moved on and we were shooting the next live-action bit. Then we had a replica of that set, but it was built off the floor. Because you can't lie on the floor and animate the puppet, it's not practical. So we had to build the set off the floor and there was a trap door in the floor, and then the camera was raised up and everything was raised up, but recreated exactly. And then the animation team came in and they animated the puppet plate, and then the VFX team glued those two shots together. So all of the stuff where there's animation, that had to all be done at the same time. So within that five weeks, we did all the live action and we did all the animation plates for the stuff where there'd be animation and live action together.
Then afterwards, while we were editing the film, we've wrapped and everyone's gone home, I shot in my lounge all of the film-within-the-film stuff. So everything you see on a laptop, the clips of the actual film and the Ash Man stuff and all that, that was all shot by me while editing the film. So I was going between London, editing, and then coming home and shooting animations. That was quite challenging to do all of that.
Effects artist Dan Martin describes the process of building and detailing the animation puppets. "They're quite clean in the fabrication at the start. And then, because it's a layered process, as we build it up further and further, we start to put those levels of sort of schmutz into them. Again, that's mostly ground silicon glass. We didn't want to affect the opacity. And then between every layer you have to make sure that everything's still moving, and you haven't blocked any joints or anything like that. "And then again, because the character (Ella) in the film world has been building these herself, she's been binding this stuff around an armature with wire. So we did use very thin aluminum wire in the manufacturer of it. But again, making sure that when we crossed joints, we weren't inhibiting movement or anything like that." Dan says that the artists creating the puppets were forced to come up with materials that could replicate the look, texture, and movement of what the puppets were supposed to be created from. " making sure that we could create those surfaces in a way that would read on camera, but also move as those things would move. We didn't want anything to de-laminate or split as it would if those materials were real. So, there was a mix of sculpture and fabrication all the way through. Like heads, anything with detail would be sculpted and cast, but then a lot of the body work would actually be fabricated into the process to be able to get that organic feel."
Part of the design concept with the animation puppets was to make them look like they were made from materials that Ella would realistically have access to. This design aesthetic would realize itself in other forms. While the Wax Girl puppet would simply have holes poked into the head for eyes, the similar Advertising Wax Girl puppet that Ella sees in Polly's studio would have eyeballs. Effects artist Dan Martin explained, "We had very basic eyes for the advertising version, and we wanted the eyes to become more and more realistic as she continued. Those eyes were white spheres, hand rolled into an eye form, and then I'd hand paint them and we'd build them up with layers of clear resin. There was no positive mold for those other than the one that we originally got the white spheres out of." The progression of the puppet eyes from simple holes, to rolled balls of clay, to realistic eyes, would also make its way into the design of the Ash Man character. "The idea is that by the end, Ash Man has harvested eyes. So, we were copying eyes from the performers, from the other actors, and there's a fox eye in him that sort of grows with him as well."
The Ash Man, is described in the film by the nameless neighbor girl as, "The man no one wants to meet." As the little girl's story evolves and Ella's animated film continues, a creepy figure begins to move through the miniature forest outside of the Wax Girl's cottage. This is the Ash Man, a disturbing, shambling figure. Effects artist Dan Martin says, "We did three Ash Mans at the smaller scale. One was essentially a spare. And then we had two different versions of him with subtle differences. He was much more meat heavy and much dirtier right from the get-go. Again, as the name suggests, he's had sort of burnt matter built into him as well."