After designing animatronics for franchises like Star Wars and Jurassic World, Gustav Hoegen and his team scaled back and happily returned to traditional design and puppetry methods for Hanna Bergholm’s indie creature-feature Hatching–the first feature film Hoegen’s Biomimic Studio worked on from start to finish. 12-year old Tinja (Siiri Solalinna) nurses an egg she brought in from the woods—a welcome distraction from her helicopter mother (Sophia Heikkilä), who obsessively micromanages the family to maintain her perfect social media presence. Then the egg grows at least as large as Tinja and a slimy and straggly bird bursts fist first through the top of the shell. The fleshy creature frightens the girl, but eventually earns her trust. Tinja even names the thing–Alli. Then Alli morphs into something else.

That such ludicrous scenes play out not in CGI but through practical effects and animatronics is a welcome surprise. Having watched so many actors fail trying to consistently gauge the level of CGI surfaces, it’s unusually effective to see actors petting, poking and wrestling with a freak-bird puppet that’s actually in the room. Hoegen went into great detail about the materials he made the creature with and the unexpected difficulties he ran into operating the puppet in even the simplest scenarios.

Filmmaker: The trailers do a good job at hiding the main creature; its animatronic design was both a relief and a surprise.

Gustav Hoegen: It’s nice to hear because I’ve only seen it while we were shooting. I haven’t seen the final result on the screen.

Filmmaker: Do you have plans to see the film?

Hoegen: I’m a father of two kids, meaning I’m not allowed to leave the house at all. [laughs] I have been invited to the premiere in Finland, and there’s an invitation from Linz [Film Festival] in Austria. But, being a dad, it’s a miracle if I get to leave London. 

Filmmaker: At what point in a given creature’s design do you enter the picture?

Hoegen: It differs from job to job, but on this occasion, Hanna approached me via email with already beautifully rendered designs—a 3D rendering of Alli that looks like it’s on a rotating table, so you can see it from all angles. In the process of building, you have a bunch of back and forths with the director about small details—skin color, what the tongue looks like, etc. But the final creature is all carefully built within that original look and design, so none of that contorted look got lost in the process of building it. I was lucky on this one. Hopefully what you see on screen is very close to what Hanna had in mind. 

Filmmaker: You made no compromises for the puppet’s mobility?

Hoegen: No actually, because how we approached bringing this puppet to life was very traditional: rope puppetry. The puppet has rods connected to the wrists, the head and the body, and it’s all held up by puppeteers. So, you don’t have to worry about internal structures supporting, say, the big head or dangling arms. That actually gave us a lot of freedom and the ability to stick to the original design, with its sunken chest and extremely thin limbs. I didn’t encounter too many technical difficulties.

Filmmaker: Were all of its movements rope puppetry? 

Hoegen: There are a lot of mechanics, but they’re concentrated in the head. That’s not something you could do manually. Apart from the hands, the only thing that was motorized was the facial expressions. The bulk of the head itself was moved by a rod, but I also hid behind the scenes with a remote control operating the beak, eyes, nostrils and tongue movement. That and the animatronic hand that bursts through the egg is all mechanical with servo motors and operated by remote control. 

Filmmaker: Did you have multiple puppets in this instance, or a single hero puppet capable of all movement in the script?

Hoegen: Ideally you want to have two puppets as a backup or for certain setups. We did a lot of awkward setups, but we only had one puppet. That was all the production could afford—animatronics are very expensive as it is. But we were able to do every setup with that puppet. I had to do a lot of outer rigging so that we could suspend it in the wardrobe or put it in the bath. It looks simple to make a creature sit in one place, like when it sits on the bed after it hatches. But the bed was covered in slime, so the puppeteers struggled to keep it seated because it kept sliding off. We actually rigged underneath the bed for two scenes. One is where Alli is sort of hunched over the girl, which is one of my favorite vignettes: you see a wide shot of the creature hunched above her, contorted. That took a lot of prepping. We had to secure the feet to the bed so that no one had to puppeteer them. Then we suspended the puppet from the rafters with bungies, just to keep the weight. Thank god we had five days of rehearsal to run through all the scenes, not only for performance but for our prep. 

Filmmaker: The puppet seems to grow over time after hatching. Because it’s only one puppet, is this just the result of camera trickery?

Hoegen: If it appears that way that’s great, that’s exactly what we intended. But it’s still the same size puppet. There’s obviously a drastic change from the hatchling into it morphing into the lead actor’s doppelganger.

Filmmaker: I just want to check since you brought up the budget—were there really no practical limitations on the design other than anything you’ve mentioned?

Hoegen: Funny enough, there wasn’t any on this one. But for something like Star Wars the creatures are often operated by people in suits. In that case, you’re already limited in how skinny you can make the creature, or in the possible proportions of the limbs–you’re tied to the proportions of the actor wearing it. But because all of the puppet’s movements were achieved externally by puppeteers, the creature could be as grotesque, as dangly or as skinny as it had to be, which was quite liberating. We didn’t have to hold back with the initial sculpt. 

Filmmaker: Alli has to be both a source of fear and comfort to Tinja. Was that a balance Hanna already nailed in the initial design?

Hoegen: It had to represent Tinja’s inner turmoil and frustrations. The contorted look reflected what she was going through with her overly controlling mother, and how she was expected to be better at everything. On the other hand, Alli also has to be endearing, because the audience has to believe Tinja could strike up a friendship with it, or a certain bond. Hanna was very specific about those two elements.

Filmmaker: In one of Alli’s later forms, the bird gets a full hair and makeup makeover. How involved were you in that look?

Hoegen: The only part we were a part of was the actual hatchling creature. Once it evolves, it’s been handed over to Connor O’Sullivan, who is a prosthetic makeup expert. What you see in the film is not necessarily done by me. As soon as it starts to evolve, Connor took over with the makeup and everything. He also produced another animatronic head for a different stage of the puppet. He did a beautiful makeup job where it looks like its jaw was torn off. They’re all beautifully sculpted silicon rubber appliances. So, I wasn’t too involved in that process, but to keep a consistent thread throughout the creature’s evolution we went back and forth on the feathering, the colors, the look of the head, etc. so that it wouldn’t drift too far from the original concept.

Filmmaker: What materials is the puppet made of?

Hoegen: Hanna wanted very realistic-looking skin. The go-to material for something like that is silicon, but for a creature that size silicon would have weighed an absolute ton. A liter of silicon can be even heavier than a liter of water, so the creature could have weighed about as much as Tinja herself. To make it puppeteerable, we decided on traditional foam latex with a paint finish as convincing as silicon. For the internal structure, my focus was again on keeping it light. The heavier the puppet is, the more laborious it becomes to operate and the more it shows in the final result. If someone’s struggling to keep the head up and they start shaking, you lose the whole illusion. The puppeteer needs to focus on the performance and not worry too much about the puppet’s weight. So internally the puppet was a combination of lightweight aluminum components, fiberglass carbon fiber and the head—by far the heaviest part—was completely filled with servo motors, aluminum levers, a silicon tongue, real bird feathers, etc. Then there are things like resins to make the molds, eyes, etc. If I went into every detail we’d need hours.

Filmmaker: I’m still trying to get my head around the whole design process. Can you walk me through the basic steps from Hanna’s design to the final puppet?

Hoegen: You blow the artwork up on paper as a size reference—say, four prints at different sizes. We asked the owner of the neighboring studio’s daughter, who was the height of Tinja, to stand next to each printed image so Hanna could pick the size she wanted. From there, I hire a sculptor for maybe five weeks and he sculpts the whole creature in clay by hand. You could 3D print it, but I still prefer to have the artistry of a sculptor and you can make mistakes that actually look good, so it has that human touch to it. Once the clay sculpt is signed off, the mold maker comes and molds the whole creature in fiberglass resin. The mold we made had 20 pieces all bolted together. I then lay in a mold that determines the thickness of the latex skin. The negative cavity that’s left between the clay skin I’ve laid in creates the core, as we say, into which I build the mechanics. 

What lies beneath the skin is a fiberglass skeleton, and that space determines how much room I have to place all my motors, hinges, etc. Once I’m happy with the endoskeleton, for lack of a better word, I have foam latex skin and clad the skeleton and the mechanics with that latex skin. We test it out, then it goes to the painter, who only took a week to do the beautiful paint job. From there it goes through the finishing hair and feather work. After several rehearsals, it’s pretty much ready to be filmed. In very broad strokes, that’s how I built that puppet.

Filmmaker: Can you tell me more about the internal Servomotors?

Hoegen: They’re like electromotors. Servomotors control the steering of remote control cars. You can move the stick of the remote control and the servomotor can copy that movement perfectly, so it’s pretty intuitive. They are ideal for bringing life to heads and eyes because of how precisely they replicate the movement of the remote control stick. 

Filmmaker: Then you also designed the eggs?

Hoegen: They were a lot easier. They’re just big polystyrene egg shapes that we put clay texture on and did a fiberglass mold. I have to be honest, the only thing we didn’t rehearse was the hatching of the creature. So, there was added pressure, but it was also the most fun part because we basically did it on the fly. On the day, we had two eggs and that was it.  We cut out a little piece, enough for it to flick a few shells off the egg, ran backstage, cut a big hole in it, put the piece we cut off back in–that was the scene where the hand bursts through the egg. Then I cut up the rest of the egg, and that’s when you see the creature come out and the shell of drop off his back. The bursting of the hand through the membrane was all practical. I don’t know if they added some shells falling off or anything [with VFX]. 

Filmmaker: So it was the actual motion of the hand that penetrated the membrane?

Hoegen: Believe it or not, I made membranes that were easy to pierce through, but they weren’t cooperating. They weren’t breaking. So, literally a few hours before we did it, I got a bottle of latex rubber, brushed it on the lid of a box, slightly panicking, put hairdryers on it so it would dry quickly, took the sheet of latex off and mounted it inside the egg. One of the puppeteers had the bright idea to make a tiny incision through which the hand could burst and rip it open. We got the shot in one go. Thank god, because it was all the latex we had. If that had gone wrong, they would not have had a second take.