Alien: Romulus is a brand-new entry in a franchise that’s been terrifying audiences for 45 years. And while it obviously leans into certain of the series’ familiar sci-fi horror elements, director Fede Alvarez—who’s been in a similar situation before, having made 2013’s Evil Dead—knew his film had to bring its own distinctive frights as well. And what better place to spring a big one than in the harrowing climax?

In a new chat with Variety, Alvarez and Romulus special effects team talked about bringing the film’s new creature to life, with an emphasis on practical effects to keep things as visceral as possible. If you haven’t seen the movie yet, here’s one of these:

The climactic monster—given the seemingly unremarkable but also horrifying name of “the Offspring”—emerges after Isabela Merced’s imperiled pregnant character injects herself with a compound that transforms her baby into something… well, Xeno-morphic. Alvarez, Romulus‘ creature effects team, visual effects supervisor Daniel Macarin, and animation supervisor Ludovic Chailloleau all worked together with one goal in mind: scaring the pants off audiences using as many practical effects, rather than CG, as possible.

A key decision was bringing in seven-foot, seven-inch tall basketball player Robert Bobroczkyi to bring the Offspring to life. “The way he moves is just unique,” Chaillouleau told the trade. “Considering his big size and the concept of what [the creature] is, he’s giving a lot of new things to watch visually, so I found that to be outstanding.”

Of course, those practical effects were enhanced with of-the-moment tech tools, but the team still aimed for subtlety. “This is a homage to the ’80s, in design style,” Chailloleau explained. “Even the models and the practical [effects], everything has to fit the way they would have done that years ago. We don’t want to look to CG, so motion is very important, because we could not animate that way 40 years ago.”

And, as it happens, the Offspring’s resemblance to the Engineers seen in Ridley Scott’s 2012 Prometheus was absolutely intended—although, again, meant to be subtle. “It’s not something that you want to directly connect,” Macarin told Variety. “But if you hint that there’s a larger story there, there’s more mystery, and maybe we’re just seeing the beginnings of those ideas, it was definitely something that we wanted to explore.”

Head to Variety to read more, including some details on how thoughtfully the Offspring’s truly disturbing maw was designed. Alien: Romulus is now in theaters.

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