The Trench is the name applied to both a fictional kingdom, and its inhabitants as a group, that escaped the destruction of Atlantis in DC Comics.
The Trench are a race of vicious, cannibalistic, ocean-dwelling creatures that were relegated to living in the depths of the Ocean and evolved accordingly.
With their first attack, they demonstrate a complete lack of empathy, relying on only the primal instinct to feed, even eating their own slain brethren.
While fighting off the creatures' attacks, the alpha marks Aquaman as food to be brought back to the ocean floor, where they originated.
[3] During the battle between Atlantis and the surface city of Gotham, The Trench were released from their undersea prison by an unknown player to be used against both sides in the war of the two worlds.
Arthur had been investigating involvement regarding the Dead King's Scepter he'd attempted to intercept during an exchange between Black Manta and a mysterious Atlantean convoy who made off with it, only for The Trench to later attack both the surface world and the armies of Atlantis at Vulko's command.
But after hearing all of this, Arthur harshly reprimanded his former adviser backhanding him into a ruined street utterly disgusted by Vulko's lack of abandon at his plans which cost hundreds of thousands their lives.
With the scepter in hand using it in conjunction with his own psionic capacities, Arthur ordered to trench back into the ocean depths.
A group of Trench were mutated, undoing their devolution into beasts to physically resemble normal humans or Atlanteans.