1. Black Manta
His nemesis, an extremely deadly tech using pirate/assassin.
Power suit, Enhanced strength, durability, underwater adaptation, electricity immunity,optic blasts, arsenal which includes bladed weapons, hook lines, electric discharges, skilled fighter and weapons expert, extremely cunning strategist, possesses uniquely designed sub and employs henchmen.
2. Ocean Master
His magic using full Atlantean half brother, former king of Atlantis.
Super human strength (lower than Aquaman), speed (lower than Aquaman), durability (lower than Aquaman), underwater adaptation, underwater speed, knowledge and use of magic, water control (through magic stuff), lightning control (through magic stuff), trained warrior (as a former king), skilled leader and strategist (as a former king), has access to Atlantean military, technology and magic.
Godling son of Poseidon, god of the seas.
Superhuman attributes (strength-class 100, speed, invulnerability, regeneration, senses), underwater adaptation, magic, divine powers, size alteration, ability to communicate with sea life,immortality, possession of magical trident, skilled warrior, vast experience through extended lifespan.
4. King Shark
Humanoid son of a Hawaiian shark god.
Superhuman strength, durability, senses, regeneration, underwater super speed, underwater adaptation, berserker rage, claws, human like intelligence and ability to speak.
Mutated criminal ancestor of Aquaman, bearer of the "Curse of Kordax".
Superhuman attributes (strength, durability, underwater speed, senses), underwater adaptation,telepathy (mainly aquatic), longevity, skilled warrior and leader, skilled swordsman (with his sword-hand), vast knowledge of Atlantis.
Deep sea diver/high tech weapons expert and arms dealer.
Power suit, underwater adaptation (through power suit), skilled fighter and weapons expert, uses wide range of gadgets and a fleet of nuclear submarines, employs big number of henchmen.
Former mercenary for hire, who gained powers through accident, famous for costing Aquaman his arm.
Power mimicry, superhuman attributes (strength, underwater speed, durability, senses all through power mimicry), underwater adaptation, cunning strategist.
Mutated humanoid shark with shape changing abilities, tried to take over Atlantis.
Enhanced strength, durability, senses, underwater speed, underwater adaptation, telepathy, telekinesis, levitation, shape changing, mental energy blasts, high intellect.
Godling leader (usually) of the Deep Six, Darkseid's elite aquatic terror squad.
Superhuman attributes (strength-class 100, durability, underwater speed, senses granted through New God physiology), underwater adaptation, regeneration, genetic manipulation, skilled warrior.
10. Deep Six
Darkseid's elite aquatic terror squad, usually led by Slig.
11. Lava Lord
Leader of the Fire Trolls, an underwater race of powerful creatures.
Superhuman strength, invulnerability, fire control, fire blasts, underwater adaptation, leadership.
12. Fire Trolls
Race of powerful underwater fire based creatures, led by Lava Lord
13. The Trench
Race of cannibalistic, underwater creatures with enhanced attributes, underwater adaptation and paralyzing poison secretion.
14. The Thirst
Magical parasitic creature connected to the Water Bearer.
Magic, necromancy, immortality, underwater adaptation, enhanced attributes, lich-like ability to drain life force and powers, high intellect.
Evil doppelganger of Aquaman from an alternate dimension.
Physical abilities similar to Aquaman (Thanatos might be stronger, Aquaman is faster), angers easily.
First Fisherman is a high tech criminal and trader.
Powersuit, underwater adaptation (through power suit), uses high tech gadgets and titanium hooks, cunning strategist and criminal.
Second Fisherman is an alien parasite.
17. King Neptune
Powerful reincarnated ancient sorcerer, predecessor to Aquaman.
Underwater adaptation, water control, magic, reincarnation, precognition, high intellect.
18. Demon Gate
Former dolphin hunter turned to cyborg, responsible for killing Aquaman's dolphin mother.
Cyborg enhancements grant super strength, high tech weaponry (blaster and remote controlled charged spear), skilled hunter.
19. The Eel
Former Gotham Criminal with telekinetic abilities, amplified underwater.
Power suit, underwater adaptation (through power suit), telekinesis, cunning criminal.
Mutant creature serving as "the avenger of the seas".
Superhuman strength, invulnerability, underwater adaptation, death touch.
King of the Lurkers, an ancient underwater race who lived beneath the seafloor.
Super strength (possibly higher than Aquaman), underwater super speed (lower than Aquaman), durability, underwater adaptation, skilled warrior (unarmed and weapons) and leader.
Extremely powerful sorceress and the leader of Atlantis during the Obsidian Age.
Underwater adaptation, very powerful sorcery, power absorption, flight, immortality, intellect, leadership, very cunning and manipulative.
Super strength, durability, arsenal that includes rockets, blades and other ranged weaponry, power suit grants underwater adaptation and flight through jet pack.
24. Marine Marauder
Both can control sea life, breathe underwater.
Twin sister of Mera from the dimension of Xebel.
Underwater adaptation, superhuman attributes (strength, durability, senses at a lower level than Aquaman), water control, trained assassin.
Sorceress and usurper of the throne of Thiera Na Oge, an Atlantean colony.
Underwater adaptation, sorcery, intellect, leadership.
Atlantean sorcerer and former prime minister of Atlantis.
Underwater adaptation, sorcery, intellect, leadership.
Mother of Monsters, an Inuit Demon Goddess who lives underwater.
Super strength, underwater adaptation, tentacle like hair, immortality, ability to control animals and mutate them to monsters, vast experience.
Consciousness sharing alien race.
Super strength, invulnerability, duplication, blast power, elasticity, ice control, telepathy.
30. Human Flying Fish
Surgically altered, former swimming champion turned criminal for hire.
Underwater adaptation, underwater super speed, flight, experienced criminal.