Needs a better description
We're all familiar with the Antichrist—the Dark Messiah of the forces of evil, destined to lead the Legions of Hell at the end of the world. He's suave, he's clever, and represents the very worst that humanity has to offer.
This guy, is a little different. Whereas the Antichrist is a monster in human form, the Beast of the Apocalypse is a literal monster, who also happens to be a harbinger of the end times. This is the kind of beast who gives the gods themselves nightmares, and in action he's liable to be a veritable engine of destruction, trampling over mortals, gods, and anything else that gets in his way. If this thing slips its leash you may as well turn out the lights and lock the universe behind you when you go, because there won't be much left. Even if this isn't the case, the simple fact of this creature's appearance means that things are about to get a whole lot worse.
For obvious reasons, such a creature is very likely to be a case of Sealed Evil in a Can. Is liable to overlap with Kill the God and Omnicidal Maniac, and will feature prominently in any Götterdämmerung. May be an Enemy to All Living Things.
See also Eldritch Abomination as well as it's variants Humanoid Abomination and Animalistic Abomination, which can all overlap with this and have.
Depending on how you class demons, Hellboy is either this or the Antichrist. Much of the imagery associated with him is taken from descriptions of the Beast in Revelations. The Ogdru-Jahad aka The Seven Who Are One, representing the Dragon of Revelations are definitely this, as are their 369 children, the Ogdru-Hem, who seek to free their parents so that they might reduce the planet to a smoldering cinder.
The Conqueror Worm, a Lovecraftian being summoned by Hermann von Klempt as part of his plan to unleash the Ogdru-Jahad, is also an example. Created by allowing a being from the void between the stars to infest the body of a dead Nazi rocket scientist, the Worm will transform all of humanity into their final, reptillian state, and then devour them, causing so much death and destruction that the Ogdru-Hem and then the Ogdru-Jahad will awaken and burn the world.
Played for laughs in Ghostbusters, when Ivo Shandor summons the prophesied demon Gozer to destroy the world because "humanity is too sick to live." Gozer procedes to take the shape of a giant Stay Puft Marshmallow Man and lay waste to the city before being banished back to where it came from.
The Beast of the Rakans in Reflections of Eterna. Up to this point it has never appeared, but it is referenced in terms of dread in almost every book.
The Beast on Angel, a huge, horned monster made out of rock, and prophesied to bring about an apocalypse. It's eventually revealed to be The Dragon to the season's real Big Bad, Jasmine, though this does little to detract from its status as an example of the trope.
Mythology and Religion
The Beast from the Sea, aka The First Beast, or The Beast from Book of Revelation, a seven-headed, ten-horned monstrosity who represents the Devil/the Dragon on Earth and wields all of his authority. Having been healed of a fatal wound it seems undefeatable. There is also The Second Beast aka The False Prophet, a ram-horned, dragon-voiced being who serves as propaganda minister to The First Beast. One could argue that Satan himself, in the form of the Dragon, is also an example.
Islam has a similar concept in the Beast of the Last Days.
Fenrir and Jormungandr in Norse Mythology. Brothers and children of Loki, the two were imprisoned because of their prophesied role in Ragnarok. It doesn't work. When the end times do roll around, Fenrir is freed (when his sons, Skoll and Hati devour the Sun and the Moon), and Jormungandr crawls onto land, and the two of them lead the assault on Asgard, where they batter down the gates and slay Odin and Thor respectively. By this point Fenrir is so large that his upper jaw hits the sky when he opens his mouth, Jormungandr can encircle the world, and the din they create is so loud that it causes the sky to split open, freeing Surtr and the sons of Muspel to make war on the gods.
One could make a case for Nidhoggr, an Omnicidal Maniac of a dragon who gnaws away at the roots of Yggdrasil with the intent of undoing all creation.
Classical Mythology: Typhon, the worst monster in Greek myth, is a failed Beast of the Apocalypse. Following Zeus' defeat of Cronos, Gaia slept with Tartarus in order to conceive Typhon, whom she then turns loose with the intent that he kill the Olympian pantheon and continue the pattern of succession within Greek myth. He fails and is imprisoned by Zeus. Whether he can break loose is never really explored.
Rovagug, the Rough Beast, God of Wrath, Disaster, and Destruction in Pathfinder. Crawling from a sinkhole at the edge of the universe, Rovagug embodies omnicidal mania, and seeks to devour all of the gods and the very fabric of reality itself. For this reason all of the gods allied to chain him in the centre of Golarion. Archangel Sarenrae through him down, while Archdevil Asmodeus holds the key to his cell.
Rovagug's Spawn are played very similarly; what he can do to the universe they threaten to do to the world, ploughing through armies and entire civilisations. Than again, with names like Festering Ulunat, the Unholy First", "Great Doom Chemnosit, the Monarch Worm", "The Tarrasque: Armageddon Engine", "Unyielding Kothogaz, the Dance of Disharmony", "Wrath-Blazing Xoanti, the Firebleeder", and "Volnagur the End-Singer" this isn't exactly surprising.
In Dungeons & Dragons, the Tarrasque was also portrayed this way (an immensly powerful monster designed for "epic" level play, which can only be killed by slaying it then asking a god to intervene and finish it off for you).
The Forgotten Realms setting has Dendar the Night Serpent, an enormous primordial serpent who exists in order to devour nightmares so that people will not remember them. At some point in the future, Dendar is destined to invade Toril and do battle with the god Ubtao at the Peak of Flame; if Ubtao loses the fight, Dendar will eat the sun and bring about the doom of the world.
In The Legend of Spyro, Malefor's plan to take over the world involves waking a massive, ancient golem named "The Destroyer".
Typhon is portrayed this way in Titan Quest, although much like his mythylogical inspiration, he never quite succeeds in clearing out all of Olympus.
The Darkova in Odin Sphere, the three headed beast of Armageddon. There's also Leventhan, the last dragon, who transforms into the bringer of Chaos during the game's final events. He's modelled in equal parts on Leviathan and Jormungandr, while his name is taken from Surtr's sword, Lavatein.
Solaris, interdimensional lifeform and god of time in Sonic the Hedgehog (2006). Divided into Iblis (the body) and Mephiles (the mind) he seeks to cause the collapse of time itself.
BlazBlue has The Black Beast. A monstrosity which wiped out a massive proportion of the human population and polluted the world with seither, meaning the survivors (minus some Beastkin who were created to fight it and can process it naturally) have to live on cities built on mountaintops. It's actually Ragna, doomed to be sent back in time and become a Tragic Monster, until the Stable Time Loop was broken by the existance of Noel.
Omega in Mega Man Zero, Ax-Crazy yet loyal Dragon to Dr. Weil. Caused the demise of 75% of all sentient life (combined total of humans and reploids). Making things even more horrifying is that Omega is exactly what Dr. Wily intended Zero to be. Sprinkle a little extra Fridge Horror on there when the reveal is made that Omega is Zero's original body, meaning that Wily succeeded.
Alduin the World Eater in The Elder Scrolls universe; a black dragon and an aspect of Akatosh the God of Time who was sired for the purpose of destroying the world at the end of every cycle so that a new world can be born in its place. Somewhat of a subversion in that he chose to neglect his duties and conquer Mundus instead of devouring it.
Toyed with, like everything else is, in The Salvation War. The Beasts of Revelation are unleashed by Yahweh and Satan with the intent that they end the world...and are cut down by the human military, albeit with more difficulty than most of the demons they've faced upto that point.
Five hats means that five tropers think it is ready to publish.
You are saying that you think this draft is ready to be published. That means the description is not ambiguous,
it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.
Is that what you meant to do?
You are saying this draft has a ready-to-publish hat it does not deserve and you are taking it back.