In the pantheon of DC heroes, all minds and eyes usually turn to heroes like Superman, Wonder Woman, and Batman. Usually, a lot of people tend to overlook guys like Aquaman, even though he was a part of the Justice League. Largely due to his goofy outfit, strange friendships, and overall "silly" powers, Aquaman is actually a pretty formidable hero who the DCEU film did justice to and has grappled with some nasty villains over the years.
While some villains don't always hit the mark, there are some, most that have come in more recent years that have risen above the rest to be seen as true villains of stature. From humans to vile sea monsters and other Atlanteans, the list goes on.
Fisherman
Lack of details with a villain can oftentimes lead to them not being as well-known or respected. The Fisherman is a hunter who targets Aquaman countless times throughout the comics.
However, there's very little information on who he actually is. When his identity's finally revealed as a nobody criminal and the helmet as an alien parasite who used him as a host, it only deepens the oddness of the character.
Dead Water
Interesting enough, Dead Water is a newer character to the Aquaman comic series. Appearing at the tail end of New 52 and throughout Rebirth, the Dead Water is alien water that is able to possess anyone or anything it touches.
Leading to monstrous transformations and a feral behavior from whoever it possesses, the Dead Water didn't last that long against Aquaman but did make a comeback when it ended up possessing Mera during "Dark Knights Metal" thanks to the Drowned.
Charybdis
Even low-level villains can go big with the heroes. Originally a human who took on the Greek monster as a codename, Charybdis became insane after his wife, codenamed Scylla, died when a bomb went off. Since then, he targeted Aquaman out of grief, intent on proving his worth for controlling sea life.
It got to the point where Charybdis shoved Arthur's hand into a pool of piranhas, causing Arthur to lose his hand and adopt the classic hook. Although Charybdis has since been inactive, his nefarious action can't go unnoticed.
Scavenger
Now, the Scavenger isn't that interesting of a villain. He's a smuggler and arms dealer, mainly small-time, who's tussled with Arthur numerous times over the years and almost always failed.
However, compared to other characters like Fisherman and the Dead Water, Scavenger has actually left an impact on Arthur. From constantly plaguing him to nearly overtaking Atlantis and destroying it, Scavenger does get a leg up over lesser villains despite his goofy suit.
Corum Rath
There are a lot of supposed kings who appear in Aquaman comics. Corum Rath is the more recent one who tried to take the throne from Arthur. Leader of the eco-terrorist group known as the Deluge who grew up in Atlantis's lowest Tride, Rath did end up overthrowing Arthur and becoming king.
Of course, that lasted a total of about ten to fifteen issues before Arthur made his comeback. That being said, Rath did get some decent development and he ended up becoming a monstrous fish creature after dealing with dark arts.
Siren
Family squabbles never end well. Considered to be one of the greatest female villains of Aquaman's rogue's gallery, Siren is the sister of Mera and sister-in-law to Arthur following their marriage. Jealous of Mera's hold on Arthur, Siren ended up being an assassin and foe against Arthur.
From impersonating Mera to teaming up with Black Manta and trying to take out Arthur on numerous occasions, Siren's proven herself to be a rival not to be trifled with and a long-lasting one at that.
Ocean Master
Siblings always have trouble getting along but Arthur and Orm seem to struggle the most. Seeing Arthur as his step-brother, the Ocean Master has seen himself as the true king of Atlantis and has butted heads with Arthur on numerous occasions.
While he seems a little whiney and obnoxious, Ocean Master has made an impact on Arthur's life, even siding with his brother when he came home to Atlantis and giving up the villain's life during "Forever Evil", making for a somewhat complex foe.
The Trench
Only about five percent of the ocean has been explored and as such, audiences and fans have wondered what undiscovered creatures lie beneath the surface. Geoff Johns explored that question with the terrifying Trench in his iconic-runs first arc.
A former tribe of Atlantis that mutated in the depths, the Trench exists only to feed and kill anything it sees. Like a movie monster out of an old film, the Trench has become a truly horrifying foe that almost got their own spin-off film in the DCEU.
Dead King
Alongside The Trench, Dead King is another addition introduced in Geoff Johns' comic run. Introduced in the final arc of the writer's run, the skeletal Dead King was once Atlan, the ruler of Atlantis, who was betrayed by Arthur's ancestors which forced him to sink Atlantis.
Years later, the Dead King rose again and retook his empire from both Arthur and Scavenger. A frightening yet also tragic villain, the Dead King ended up being a powerful foe with devastating abilities and a long-lasting legacy that left its mark on Arthur.
Black Manta
Revenge is always a powerful motivator and it can always shape the best villains. A treasure hunter like his father before him, David Hyde became obsessed with killing Aquaman after the Atlantean killed his father in a fit of rage, leading to the birth of the vicious Black Manta.
Forever scarred by Arthur's trident, Black Manta seeks the death of Arthur and the destruction of Atlantis. Having teamed up with the Legion of Doom and gotten the upper hand on Arthur multiple times, Manta's vendetta is still ongoing and may, like the inky depths of the sea, never end.