Frank Herbert’s science-fiction novel Dune is a true giant in genre literature, with a tremendous effect on pop culture at large. One of the most iconic elements from the book, and an image constantly referenced in other media, is the giant sandworms. The ugly, desert-dwelling creatures certainly look cool, but they’re more than just scary monsters that pop up every now and then. In fact, they’re extremely important to the plot and the very fiber of the Dune universe.

Here is everything you need to know about the sandworms from Herbert’s novel, and what we can expect from them in Denis Villeneuve’s upcoming film adaptation.

Arrakis in David Lynch's DuneUniversal Pictures

Where do the sandworms live and what do they look like?

The sandworms are native to the desert planet Arrakis, the only location in the known universe where they are found. They are created when their larval form, known as sandtrout (or Little Makers), band together in stores of water beneath the surface of Arrakis. This makes a liquid chemical that combusts above ground, creating a mixture known as pre-spice mass. (Remember this—it will come in handy in a minute.) Any sandtrout that survive this process then metamorphasize into sandworms.

It’s believed that the full-size creatures live to be thousands of years old. Water is toxic to the creatures, who eat sand and other organic compounds in the Arrakis desert. They grow up to 750 meters in length and have thick, orange-colored skin. They are said to have a smell that’s “strong, flinty, cinnamon,” similar to that of spice melange.

Universal Pictures

Why are they so important?

Speaking of spice melange, that’s part of why these beasts are so integral to the Dune universe. That pre-spice mass we mentioned before? After that comes to the surface of Arrakis and mixes with the chemicals in the surface environment, it creates the powerful substance known as spice melange. This spice is the most precious material in the entire known universe, as it gifts its taker with the abilities of prescience and long-lasting life. It also makes interstellar space travel possible.

Because their lifecycle is key to the production of spice melange, the sandworms are feared and worshipped by the Fremen, one of the human populations on Arrakis. They consider the sandworms to be godlike. And because the worms mostly stay below ground, only coming to the surface to defend their territory, spotting one is considered rare, which only feeds their mythos.

Warner Bros. Pictures/Legendary Pictures

What can we expect from the sandworms in the new film?

We have reason to believe Villeneuve’s Dune will pay its utmost respect to the sandworms. Why? Because according to a new interview with Empire magazine, the director said he and the effects team spent a full year perfecting the look of the creatures.

“We talked about every little detail that would make such a beast possible, from the texture of the skin, to the way the mouth opens, to the system to eat its food in the sand,” Villeneuve said. “It was a year of work to design and to find the perfect shape that looked prehistoric enough.”

An image that ran with the Empire article showed Paul Atreides and Gurney Halleck in what must be their first encounter with one of the worms.

We can’t wait to see how everything came together, and what this new iteration of sandworms will look like, when Dune hits theaters on December 18, 2020.

And ahead of that release date, be sure to read Dune along with Nerdist Book Club this spring! We’re about halfway through Herbert’s novel, but there’s plenty of time to catch up. Find out more information about the read-along here.

Featured Image: Universal Pictures