Fictional race by DC Comics
The Monitors are a group of fictional comic book characters, who appear in books published by DC Comics.
They are based on the Monitor and the Anti-Monitor, two characters created by comic book writer Marv Wolfman and comic artist George Pérez as the main characters of DC Comics' "Crisis on Infinite Earths" limited series. They are a group that watches all aspects of the Multiverse, past and present. Most importantly, they seek to prevent crossovers between the universes, as was common before "The Crisis". The Monitors first appeared in "Brave New World".
They are in some respects similar to the Watchers of the Marvel Universe, though they take a more active role as opposed to simply observing.
Fictional history.
Origins.
One of the Monitors appears in shadow on the cover of the "DCU: Brave New World" Special; the first few pages show the Monitors' satellite appearing over New Earth. In the final pages of the comic, five Monitors are revealed, one of whom calls the group "the Monitors." One of the five is noticeably different from the others; although his back is turned, he resembles the Anti-Monitor. This Monitor is later shown in "Supergirl" to only dress like the Anti-Monitor. In "Ion" #9, the Monitors are shown to be a society of many different Monitors. There are 52 in total, one from each of the new universes. In "Countdown to Final Crisis" #48, when a large group of Monitors gather together, it is shown that each of them is physically different from the others in at least a small way. The most extreme example, apart from the one dressed like the Anti-Monitor, is one who appears to be a humanoid giraffe, suggesting he is the Monitor of a modern equivalent of Captain Carrot's Earth-26.
When the tower that Alexander Luthor used to recreate the original Multiverse during the events of "Infinite Crisis" was destroyed, a "seed programming" was activated that created a Monitor for each of the 52 Earths of the new Multiverse born in that moment. Since this new Multiverse consisted of 52 identical Earths at the time of its forming, all 52 Monitors would have been identical. However, following the events of "52", the Monitors began to evolve and acquire increasingly divergent identities in physicality and disposition. As the Monitors evolved, their story became more complex, a "self-assembling hyper story".
In the end, the revised origin of the Monitors took this form: in the beginning, a gigantic vast intelligence named Monitor, but referred to in places as "Overmonitor" or "Overvoid", discovered the Bleed and the Multiverse within, a 'flaw' at its heart. Disturbed, it sent out a probe in a similar form to that of the original "Monitor" from "Crisis on Infinite Earths" that fed back the chaos of every story of the Infinite Earths all at once; overwhelmed by the very idea of a "story", the Monitor recalled the probe and sealed off the Bleed by creating the Multiverse Machine (or "Orrery of Worlds"), but his contemplation of the workings of the Machine (doubtless combined with the established fact that the Monitor was linked to all positive matter) resulted in the generation of the World of Nil, populated by powerful vampiric beings with a vast and epic history, living and continuously evolving manifestations of the Monitor's thoughts, who see themselves as "descendants" of the Monitor himself. In their world, time moves - from a human point of view - much faster, so much so that the period between the original Crisis and the Final Crisis encompasses the rise and eventual fall of a vast and complex civilization.
In later interviews, the author of this revised origin of the Monitor race, Grant Morrison, explained it as a metafictional comment on the DC Multiverse as both a living being and a fictional creation, with the Overvoid as a single or multiple pieces of blank white paper, reacting to the ink stories being forced upon it:
Monitor Sightings.
The Monitors have made the following additional appearances: 
Individuality.
In "Countdown to Final Crisis", one of the storylines follows the Monitors in their headquarters. One Monitor has taken it upon himself to eradicate inconsistencies within the universes, characters such as Duela Dent, whom he kills. At first, the other 51 Monitors are more devoted to merely watching the multiverse and intervening only when truly necessary. Throughout the "Countdown", each of the Monitors begins to develop disparate personalities and physical characteristics which reflect (to some extent) the nature of their universe and each Monitor takes a name for themselves. In "Final Crisis", one Monitor reflects that this is because interaction with the worlds of the Multiverse has allowed time itself—beginnings and endings—to enter their haven. Notably, Rox Ogama, disciple of the Dark Monitor, Mandrakk, is charged to look after the universe of "", in which Batman also becomes a vampire.
"Bob".
The Monitors begin to debate over being reactive and proactive regarding the world jumpers and death cheaters. The proactive Monitor (in favor of killing the anomalies), manages to sway sentiment towards his side. He dispatches a Forerunner, a member of an experimental race of warriors bred by the Monitors, to kill Jason Todd and Donna Troy. They are stopped by one of the reactive Monitors only because the Forerunners must obey a Monitor due to their genetic breeding. The reactive Monitor, Jason Todd, and Donna Troy meet with current Atom Ryan Choi to search for Ray Palmer in the Nanoverse (or "Palmerverse"). Here, Donna Troy realizes that, while this Monitor has done so much for the Multiverse already, no one knows his name. The Monitor claims to not have a name, and Jason Todd takes it upon himself to name him "Bob." When the Challengers find Ray Palmer, Bob reveals his acts of assistance to be a ruse, and attempts to kill Palmer. After Palmer and the Challengers escape, Bob is confronted by his fellow Monitors. Solomon attempts to absorb Bob into his being, but ends up killing him instead.
This Monitor of New Earth bears the closest resemblance to the original Monitor, that world being the combined total of all the universes the original Monitor watched over.
Bob the Monitor is mentioned in pre game dialogue between Red Hood and Power Girl in "Injustice 2".
Solomon.
Monitor of Earth 8. As a result of Bob's actions, the other Monitors take a more aggressive approach to maintaining the multiverse. Seeing it as a necessity under the circumstances, they all take on names as Bob has. Rallying behind the Monitor of Earth-8, now calling himself Solomon, they begin to fear that it is not only the anomalies that they must face, but also the virus infecting Karate Kid, Monarch's growing army, whoever is responsible for Jimmy Olsen's powers, and the possibility that a single individual may be behind all of these events. With the help of a female monitor, Solomon convinces the others to prepare for war. After Solomon's attempt to absorb Bob, the other Monitors voice their disapproval. Solomon reveals that he planned to join with his fellow Monitors and become the Source. The Monitors are then interrupted by Monarch. As the Monitors battle his army, Monarch reveals to Solomon that his actions were the catalyst to the creation of his army. Solomon, greatly distressed, flees to the Monitor satellite, where he is snubbed by the remaining Monitors. Solomon is then approached by Superman-Prime. Solomon tells Prime that Monarch is destroying the perfect universe, and Prime flies off to fight him. Darkseid then appears and offers Solomon assistance. They go to Apokolips, where they watch events unfold. While the planet is assimilated by Brother Eye, and a large part of it is destroyed by Pied Piper, Darkseid reveals that it was Solomon who attacked Captain Atom in Blüdhaven, triggering his transformation into Monarch. When Darkseid reveals his plans to control the Fifth World, Solomon appears to the heroes still on Apokolips, warning them of the danger, and teleporting them back to Earth. It is later revealed that the Earth he sent them to was the reconstituted Earth-51, as a way of stopping part of Darkseid's plan. Solomon is then seen on the Monitors' satellite, patiently awaiting Darkseid's next move. After Darkseid's death, Solomon creates a small monument to him on the Source Wall, and patiently begins planning anew.
Nix Uotan.
Monitor of Earth-51, Nix Uotan is the "youngest" of all the Monitors. He is first seen at the beginning of "Countdown to Final Crisis", a nameless Monitor with only minimal distinguishing features, seeking guidance at the Source Wall regarding the rising tensions in the Multiverse. Being informed by the Source that the "Great Disaster"—a long-foretold event that would herald the end of the Monitor race—is approaching and that only Ray Palmer can stop it, he determines to keep Palmer's presence on his world a secret from his brethren. He is next seen on Earth-12, where he confronts Bob in an attempt to stop his efforts to find Ray Palmer, who is "living a life of no consequence" in the relative safety of his own assigned world. When the Challengers (Donna, Jason, and Kyle) are brought to Earth-51, at last finding Ray Palmer there, Bob and Solomon bring the Monitors to this Earth in hopes of destroying Palmer. The Monarch uses this opportunity to put his Multiversal army at war against the Monitors, a war that ultimately lays nuclear waste to all of Earth-51. Nix Uotan sends the Challengers to Apokolips to confront Darkseid; he is left alone in his desolate universe, and begins its rebirth. After events on Apokolips, the Challengers are sent to the reborn Earth-51 by Solomon, infecting it with Karate Kid's Morticoccus virus, and causing the "Great Disaster", thus destroying that world a second time. In the final issue of "Countdown to Final Crisis", the Challengers (now Donna, Kyle, Ray, and Forager) confront the Monitors with the promise they will be watching them and protecting the Multiverse; Nix Uotan defends their choice, and joins their ranks in a reconstituted group of Challengers.
At the start of "Final Crisis", Nix Uotan is punished for failing to protect Earth-51 from destruction and is banished into the Multiverse by the other Monitors; he awakes as a human on New Earth. Having only partial memories of his past, he begins searching for his "word of attention," a word that he believes will return him home. After Darkseid spreads the Anti-Life Equation to the Earth, he is captured by Darkseid's forces for being, apparently, immune to Anti-Life. There a man with hairy, dexterous fingers in the corner makes him remember his Monitor love, Weeja Dell. When the Justifiers come to get him, another man (Metron) in the room solves a Rubik's Cube in 17 moves (ostensibly one "less" than the smallest possible number of moves necessary to solve any Rubik's Cube), and then emits a burst of blue light. After that it is shown that Nix has apparently received new powers as a Multiversal Monitor of the Fifth World, with monitors around his head showing the events that are happening across the Multiverse. "The Judge of All Evil" confronts Mandrakk in "the black hole at the base of creation" with an army of Supermen recruited from across the Multiverse that is reinforced by Uotan restoring the Zoo Crew (then trapped as ordinary animals) by returning their humanity, costumes and powers, and restores Earth-51 before the world of the Monitors comes to an end. At the end of Final Crisis, it is revealed that Nix Uotan is actually the son of Mandrakk.
In the end, the world of the Monitors is destroyed, as Nix Uotan holds Weeja Dell, telling her that Superman's wish was "for a happy ending". Nix Uotan is once again reborn as a human in Metropolis, which during recent interviews with Grant Morrison state he is now the lone Monitor retained by the Over Monitor to maintain his function.
Uotan's name, pronounced "Wotan", is derived from the name of the Norse God of Writing, Wotan, who similarly underwent great trials in order to be reborn as a purer, wiser being.
Dax Novu/Mandrakk.
Known initially as The Radiant One, the first son of the limitless Monitor, who first mapped the Multiverse. It is not made clear whether he is the same being as the original, nameless "Monitor" of "Crisis on Infinite Earths", or the original "probe" created by the Overmonitor intelligence