Spoiler alert! We're discussing plot points integral to 'Aquaman,' so beware if you haven’t seen it yet.

In “Aquaman,” Jason Momoa’s tatted-up Justice Leaguer isn't the only awesome warrior dude to get an origin story.

Aquaman’s archvillain from the comic books, Black Manta (Yahya Abdul-Mateen II), also gets an important albeit short character arc in director James Wan’s underwater adventure. "Batman has a lot of really interesting supervillains, but what makes Aquaman exciting for me is having antagonists who come from a unique place," Wan says.

In his first big scene, the seafaring superhero busts up a bunch of pirates, including Manta, who’ve boarded a Russian sub, and amid the fighting, Manta’s dad (Michael Beach) is pinned. Despite the son’s pleading, Aquaman refuses to save him as the ship sinks.

Understandably irked, Black Manta gets in cahoots with Aquaman’s half-brother, Atlantean King Orm (Patrick Wilson), who has designs on being the Ocean Master and outfits Manta with technology that turns water into lasers. (For real, it’s pretty cool.) With the help of an Atlantean hit squad, Manta tracks Aquaman down in Sicily, unleashes laser bursts from his iconic helmet, but the bad guy gets his butt whupped pretty bad, never to be seen again.

That is, until the mid-credits scene.

Seriously, THIS IS YOUR FINAL SPOILER WARNING. (And also a fine time for a GIF showing Black Manta arriving for battle in baller style.)

Following the climax where Aquaman finds the Lost Trident of Atlan, defeats his bro in an all-out underwater battle and becomes the king of Atlantis, the action shifts to Manta, who is rescued, bandaged up and recovering under the watch of Dr. Stephen Shin (Randall Park). A marine biologist from the comics, Shin – who was seen fleetingly early in the movie on a news broadcast – is obsessed with finding Atlantis and asks Manta for insight on his Atlantean gadgetry. “Sure. But first, you've gotta tell me how to find him,” says Manta, tossing his knife (one inherited from his grandfather) at a newspaper article with the headline “Who Is Aquaman?”

It sets up Black Manta’s quest for revenge to continue in an “Aquaman” sequel. Wan understands that some fans would have preferred to see more of him, Shin and others from the Aqua-pantheon, but “there's no need to use all of it. Already, I feel like I have so many things I needed to kind of put in there just in terms of the origin. The main story line needed to be about the throne of Atlantis. And if it's about the throne of Atlantis, then that means that his antagonism is with his brother, King Orm.”

That said, “I knew going into an ‘Aquaman’ movie, fans would riot if I didn't have Black Manta in this someplace,” Wan says. “I had to walk that tightrope of, 'OK, if I'm going to bring these characters in, how can I make the story overall cohesive, and it doesn't feel like I'm just jamming this character in there just for the sake of jamming him in there?' ”