Aquaman has never garnered the same widespread exposure as Batman and Superman, but that’s about to change when his solo movie hits theaters this December.

Warner Bros. shared the movie’s first trailer on Saturday, and it is epic. There are sharks, seahorses, submarines, and plenty of action. Plus, we finally learn about Aquaman’s backstory and why he’s so fond of the surface world.

Here’s Aquaman’s official synopsis:

From Warner Bros. Pictures and director James Wan comes an action-packed adventure that spans the vast, visually breathtaking underwater world of the seven seas, “Aquaman,” starring Jason Momoa in the title role. The film reveals the origin story of half-human, half-Atlantean Arthur Curry and takes him on the journey of his lifetime—one that will not only force him to face who he really is, but to discover if he is worthy of who he was born to be…a king.

Aquaman became a fan-favorite after his turn in Justice League, and Warner Bros. is hoping to capitalize on audience goodwill in his solo movie. Judging by what we’ve seen, the movie is going to be a lot of fun. And, damn, Black Manta looks downright dangerous in that suit.

Aquaman hits theaters on December 21.