The amphibian superhero we’ve been waiting for is finally here. Warner Bros. debuted the first trailer for its standalone Aquaman trailer, starring Jason Momoa as the titular hero, during its Hall H presentation at San Diego Comic-Con on Saturday. Aside from a few promotion stills, this is our first look at the new movie, and it looks pretty great.

As expected, Aquaman will be an origin story, meaning it presumably takes place before the events of Justice League. The trailer opens with some narration from Momoa explaining his early childhood.

“My father was a lighthouse keeper,” he says. “My mother was a queen, but life has a way of bringing people together.”

We then see Aquaman as a young child living in the human world. On a trip to the aquarium, he’s bullied by a few larger boys and in response he commands a giant shark to intimidate them, inadvertently revealing his powers to the world.

The trailer then moves ahead in time as Aquaman returns home to Atlantis, where his brother has claimed the throne and plans to invade the surface world. We get a few very cool looks at the underwater world, including an arena where Aquaman fights his brother and a bunch of big scary fish monsters.

After the trailer ended, Comic-Con attendees got an exclusive look at some extra Aquaman footage, including an “extended chase and fight scenes,” according to Bleeding Cool’s live blog.

This movie can’t come soon enough. Check out the trailer below.

Aquaman hits theaters on December 21.