You may think you know all there is to know about Star Wars: The Last Jedi‘s adorable and insanely merchandisable Porgs. But what if everything you know is wrong? For example, it’s a common assumption that the Porgs were created in order to digitally mask the puffins that lived on the island of Skellig Michael. But according to ILM animation supervisor Stephen Aplin, that isn’t totally accurate. Yes, the puffins inspired the creation of the Porgs, but, he says, “I don’t think there were actually any shots where puffins were puffins were replaced with Porgs. What we did have was practical puppeteered Porgs. For pretty much 80 to 90% of the shots, they were puppets. They were on set at the time, and Rian [Johnson] loved the way that the puppeteers made the Porgs move. He found them just hilarious. They have something about their movement which just makes you laugh when you look at them.”

So what makes the darn things so cute? Aplin breaks it down very simply: “They’re such a basic design—they’re a potato with stick arms and legs and big eyes. It makes me laugh just thinking of them.” As an animator for the few scenes that did need them to be CG, he took great care to duplicate the live-action versions. Johnson, he says, “was very keen that that magic that had been brought by the puppeteers to the Porgs wasn’t lost.”

Aplin worked on all three Star Wars prequels, but only recently returned to the franchise for The Last Jedi. Asked about the perception that the prequels leaned more heavily on animation than the newest ones, he says there’s some truth there. “At the time when the prequels were made, it was such new CG and the idea of doing digital characters, especially, was something that was very fresh at that time,” he says. “And I think George [Lucas] was really excited to be able to play and open that tool box, and try those ideas out. I think in the meantime, there have been so many directors who have been burned by digital characters that haven’t been successful, and audiences don’t have any patience for it.”

The animation they use nowadays is harder to spot, though director Rian Johnson wasn’t convinced at first. Aplin says, “He definitely was holding up his hands, first of all, and very adamant that he wanted to keep it as practical as possible. We showed him we can make something look as practical as you want: it can be digital and still [look] practical. We don’t have to go to the opposite end of the spectrum. Once he saw we could do that, then he sort of opened the door a little bit, and by the end of the film, he knew that he could adjust his performances where he needed to, but it wasn’t going to suddenly become something that wasn’t believable to the audience anymore, or pull the audience out. He felt safe with us.”

Asked what his biggest challenge was, Aplin first mentioned Snoke, pointing out that it’s tough to add “as much subtle detail and micro expression—and everything which you would expect from a live-action performer—when you have a camera that’s about a foot away from his face. Then we had to really be on our top game, to make sure that that felt real.” But the toughest moments of all involved the llama/horse hybrid racing creatures known as Fathiers. “We had 30 Fathiers in one shot,” he says, adding “it’s a huge balancing act to an animator to tackle those shots, to make sure we have correct continuity, and that they feel weighty running at 50 miles an hour when they’re twice the size of a horse, and leaping on vehicles and trashing casinos. And then we had to also work on their implementation of getting our live-action actors on the back of one of them, which is a whole other technical challenge which is incredibly difficult.”

When Nerdist asked Aplin about BB-8, however, we got an unexpected casual bombshell. “There are a few other tricks which we reintroduced on this film that—well, he or she, we still aren’t quite sure—there’s an argument that’s always ongoing with BB-8. I think that the consensus is she, but I don’t know.” BB-8 was initially conceived as female, but has been referred to as male in most key merchandise. That the actual animators still debate this is noteworthy, and maybe it’s something we never should know definitively.

For the record, however, this writer’s wife seized upon the remark as confirmation of a fact she had always insisted upon.

Star Wars: The Last Jedi is currently available as a digital download, and hits Blu-ray March 27th.

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• Luke, Rose, and Maz Kanata join Forces of Destiny.

Images: Lucasfilm