Every time James Wan gets a big budget action movie, people joke that he’s going to turn it into a horror movie. They said that when he got Furious 7 and they said it about Aquaman. But in the case of Aquaman, they were kind of right.

While Aquaman is a big, visual effects comic book bonanza, Wan was able to scratch his creature itch by creating the undersea characters of Atlantis.

“The race of underwater Atlanteans came from the comic but in terms of the way they look, it was all designed from scratch for the movie,” Wan told Bloody-Disgusting. “It was all adapted for the movie.”

Some of the main races of Atlanteans you’ll meet in Aquaman are the Trench (above), the Brine and the Fishermen.

“[I used] Geoff Johns’ run New 52 as the springboard to then go off and design the world, design the characters, working closely again with all these artists to shape the way they look,” Wan said.

“I knew going into this that the Atlantean race, the Xebelean race would be more ‘surface dwelling human looking’ but I wanted the other nations, the other kingdoms to look more like underwater people. I started embracing the idea that there’s a race of people that are merpeople, mermaids and mermen. Then there’s another race like the Brine which are basically giant crab people, a race of crustaceans basically. Obviously, the Trench are more classical sea monsters. That was fun, designing each different look for the different worlds.”

By default, Aquaman has to give most of its attention to Aquaman (Jason Momoa), but there are whole movies’ worth of stories about the other creatures of Atlantis.

“It’s not just how they look physically,” Wan said. “What do their cities look like? What kind of ships would they ride in? What kind of animals do they have? A lot of thought and a lot of time was spent in the tiny little details that even though it might not be in the overall narrative of the story, they’re there in the visual designs. I really wanted to create a world that’s uniquely its own. In the same way when you watch Star Wars you go, ‘This is its own world.’ It doesn’t feel like it’s part of the world that we’re from, right? Same for movies like Lord of the Rings as well. Those movies were obviously in the back of my head in terms of world creation and what they did. Going into this, everything about this I designed from the ground up, from Atlantis, the sea creatures, the machines to the ships and vehicles, all the sea monsters. They were fun to do.”

Wan even gave the Silver Age character Topo the octopus a blink and you’ll miss it cameo.

“In the Silver Age, Topo is a pet/friend of Aquaman,” Wan said.

“He does really funny things. He plays lots of musical instruments, just weird and wonderful stuff like that. So I was like, ‘How can I just have this guy make a cameo but in a fun way?’”

H.P. Lovecraft gets a shoutout in Aquaman too. Look on Aquaman’s father’s table for a Lovecraft paperback.

“Definitely I’m a big Lovecraft fan,” Wan said.

“A lot of the sea monsters in this were very Lovecraft inspired. It just felt like the right thing to do, a fun thing to do.”

Don’t expect a cameo from Lovecraft’s famous sea monster though. “There’s no Cthulu if that’s what you mean,” Wan said.

You should, however, scan the ocean floor for other James Wan Easter eggs, but Wan would not admit to throwing some inside jokes at the bottom of the ocean.

“I don’t know what you mean and I deny anything and everything,” Wan laughed.

Aquaman opens Friday, December 21.