When the sun sets and the moon rises, these DC villains crawl out from the darkness. These beings of unimaginable horror come into the world, escaping from the nightmare realms of our minds and into the waking moments of life. If not for the heroes in their colorful costumes, these evil creatures could swallow up the world and trap everyone in an eternal living hell.
These are the things that go bump in the night. The monsters that haunt the night, searching for victims. The beasts that want only to destroy all that lies before them. They exist only to cause fear, panic, and terror, and they revel in it. They are the villains that scare even the most courageous heroes. They are nightmares given form, forever etched into the human psyche to make us fear the dark.
10 Robin King
A recent addition to the DC Universe that made his debut in Dark Nights: Death Metal, the Robin King is a creature of pure nightmares. When a young sociopathic Bruce Wayne saw an opportunity to start his career of murder, he took it. He not only killed the man who threatened his parent's lives in an alley but his parents as well.
The evil child then went on to kill Alfred and become the Robin King, a young boy with a utility belt filled with gadgets that can kill every superhero. Now, as The Batman Who Laughs turns into a new form of evil, the Robin King leads the charge against the heroes.
9 Superboy-Prime
Imagine a Clark Kent who was not raised on the Kent Farm. Imagine a Superman who was never taught to respect others or to use his powers only for good. Then imagine that same boy being trapped in an empty reality for decades, watching as the world he helped save gets darker and darker, driving him mad. When Superboy-Prime was freed from his self-imposed prison, he lashed out at the heroes, killing a number of them during the Infinite Crisis.
Superboy-Prime is the greatest fear every hero of the DC Universe feels; a Superman who has no morals and no problem with killing others to get his way. He is unbridled rage, looking for revenge against those he feels have slighted him, and that includes every living person.
8 Trigon
Centuries ago, a group of humans abandoned life on Earth and opened a doorway to the interdimensional realm called Azarath. Looking to create a society built on pacifism, these humans expelled the darkness that existed in their souls and cast it into the nether-realms. That dark energy formed into a sentient being and, when summoned by an alien race, it went to them and impregnated one of their women. The child that came from this mating was named Trigon.
Trigon went on to slaughter the aliens that helped create him, leaving their world a lifeless husk in space. He followed that up by destroying every planet in his dimension. With nothing left to kill there, Trigon traveled to the DC Universe looking for more lives to snuff out. Time and again his evilness has been stopped by his daughter, Raven.
7 Darkseid
When the Old Gods died, the New Gods were born. On the planet of Apokolips, Uxas, known today as Darkseid, was born a prince; however, as the youngest of two sons, he would never be king. Craving power, Darkseid killed his brother and mother, taking control of his world. Darkseid subjected his people, forcing them into an endless war with the planet of New Genesis.
When Darkseid first met the Martians, he learned of their belief in a Life Equation that fills everything with light. Darkseid theorized that if there is a Life Equation, then there must also be an Anti-Life Equation that would destroy all living things. It has become Darkseid's obsession to find the Anti-Life Equation and use it to rule the universe.
6 Upside-Down Man
When the two sides of magic were created, the Upside-Down Man was born. As the avatar of dark magic, the Upside-Down Man is a disfigured creature that represents what dark magic can do. The Upside-Down Man was trapped in the Dark Dimension by his sister Hecate, the avatar of light magic. There, he found the Otherkind and turned them into his own army, waiting for the right time to strike.
In his first strike against reality, the Upside-Down Man destroyed Nanda Parbat, infected the Parliament of Trees, and killed Detective Chimp, Swamp Thing, and Constantine. Wonder Woman and Zatanna, the only remaining members of Justice League Dark, were able to defeat the Upside-Down Man and bring their teammates back to life, but now everyone fears what will happen if this monster returns.
5 Solomon Grundy
Fifty years after Cyrus Gold was murdered and his body is disposed of in Slaughter Swamp, his decaying corpse rose from the dead as Solomon Grundy. This is the first known form of the creature, but not the last. Each time Solomon Grundy is killed, he returns anew.
While he is most often a being of pure hate, there are times that Grundy has returned as a gentle giant, most notably when he became friends with Jack Knight and Mikaal Tomas, two men who were both known as Starman. Like Swamp Thing, Grundy is a Plant Elemental given life by the Parliament of Trees, but because Cyrus did not die in flames, he is an imperfect creation, an anomaly that feeds on rage and destruction.
4 Doctor Destiny
John Dee was a low-level criminal who dabbled in science until his mother gave him the Materioptikon, a blood-red stone with reality-warping powers that can create entire universes out of dreams and memories. Taking on the name Doctor Destiny, John Dee became a supervillain who often butted heads with the Justice League.
The more Doctor Destiny used the Materioptikon, the more it ate away at his body, leaving him a twisted skeleton of a man. As a side-effect of the stone, John Dee cannot dream, and the lack of dreams has driven him insane, making his mind as twisted as his body.
3 Nekron
The Lord of the Unliving, Nekron is not Death, but the physical embodiment of the concept of death. One of the most powerful forces in the universe, Nekron was trapped in the Land of the Unliving by the Guardians of the Universe. When he escaped, Nekron raised an army of the undead to destroy the universe but was stopped by the Green Lanterns.
Nekron once again escaped the Land of the Unliving and created the Black Lantern Corps; an army of zombies with power rings. To battle the heroes of the universe, Nekron reanimated many of their dead comrades, including the Elongated Man, Ted Kord the second Blue Beetle, and the Superman from Earth-Two.
2 Kryb
A member of the Sinestro Corps, Kryb has become one of the most terrifying foes of the Green Lanterns. Kryb revels in targeting members of the Green Lantern Corps who are also parents. She likes to murder them, and then steal their children and keep them in the pouch on her back.
Kryb can also secrete a yellow liquid that takes over the minds of Green Lanterns if they come into contact with it, allowing her to control them. Kryb's very existence creates unease in many of the Green Lanterns, weakening their will. They fear what will happen to their loved ones if they are killed in the line of duty.
1 Joker
Of all the evil in the universe, the Joker is comparatively weak. He has no superpowers, no ability to disintegrate people with a look or crush planets with his bare hands, but still, he is one of the most feared men on Earth. What makes Joker so terrifying is that no one, not even Batman, knows what he will do next.
Joker is the embodiment of chaos. He will just as soon kill a baby as he would have a snack. To call him insane is to underrepresent the depravity of this monster who finds joy in murder. There is no soul inside the ghoulish body of Gotham City's greatest killer, only darkness that makes even the gods shiver.