An entity appears that states or is thought to be God. Not just any deity, but the supreme deity, potentially God with a capital-G. They're legitimately divine, so they seem like the real deal. Until it's revealed that there's Always a Bigger Fish; the real supreme deity shows up and "God" is shown not to be on top of the Divine Ranks as people thought. While a deity, they aren't the deity. In short, they're Not Quite the Almighty.
Why the mistake? It could be that "God" was the most powerful being in the world/universe as we know it, but there's a higher realm that the true Top God was the master of, which people didn't know about (possibly even the assumed top god). Maybe God God was absent or lazy and the lesser God was just filling in their role, or the God God retired and the lesser God inherited the role. Or maybe the lesser God is on an ego trip and assumes he's superior to all gods, and managed to convince everyone he was.
While the Not Quite Almighty's attitude could be a case A God Am I depending on the power gap, that's usually reserved for mortals who think they are gods. The Not Quite Almighty is a god, just not the mightiest of them all. If the Not Quite Almighty proves to be The Omnipotent, the actual Almighty is Even More Omnipotent. When something is more powerful than a god but not one itself, they're Above the Gods instead(which even the true Almighty might be subject to). Sub-Trope of Always a Bigger Fish. When they are the real supreme being but have an equal and opposite, the latter's a case of The Anti-God. Compare Divine Ranks, which deals with the chain of command of deities in general, and God Guise, where a mortal is posing as a deity. Compare Actually, That's My Assistant for the more mundane version.
- Dragon Ball: The highest god rank revealed is initially the Supreme Kai, the gods of creation, of whom Shin is the only survivor (and later Old Kai when he's released from the Z-Sword. However Dragonball Z Battle Of Gods reveals they are just the counterparts to Beerus the god of destruction, who is far stronger than any Supreme Kai or character to date, with his attendant Whis being far stronger than even him. The sequel series Dragonball Super further reveals that while they are the supreme gods of the universe, said universe is only the 7th of 12 universes, all of which are subject to Zen'o the Omni-King, who even Beerus is terrified of.
- Tenchi Muyo!: The Chousin are a trio of sister deities who created the multiverse, and are super-dimensional deities that are The Omnipotent to the mortal world. However they theorized that there might be a being superior to even then. They're ultimately proven right in the Supreme Being (or "Kami Tenchi"), Tenchi's inner power, which is as omnipotent to the Chousin as they are to mortal beings.
- DC Year of the Villain: The main Big Bad is Perpetua, a Cosmic Entity who created the multiverse for nefarious purposes. Having created the Monitor/Anti-Monitor/World Forger and by extension the DC Multiverse, she's the Mother of the Multiverse. However even Perpetua is one of many Super Celestials in the greater Omniverse, and is superseded by the Source. She was sealed in the Source Wall by an agent of the Source for trying to pervert the natural order, and is motivated in part to avoid the Source's judgement.
- The Sandman: The Endless are not gods, they existed before humanity dreamed of gods and will still exist after the last god is dead. However they still pale in comparison to their parents Time and Night, Lucifer is strong enough to intimidate Dream of the Endless, and The Presence is greater than them all.
- Spawn: God and Satan are introduced as siblings who are the most powerful beings in the universe. Eventually it's revealed they're only the second most powerful beings. It's their creator, The Man Of Miracles, who's the true God of the setting.
- His Dark Materials: The Authority, presumed to be God, is actually the oldest and (originally) the most powerful of the Angels, who falsely claims to be the creator the universe. The actual creative force is a more abstract thing that manifests as the "Dust".
- Job: A Comedy of Justice: God and Satan are revealed to be brothers who are merely juniors in a vast Celestial Bureaucracy. Earth is essentially a school project between the two.
- The Stormlight Archive: "The Almighty", supreme being in the planet Roshar's dominant Vorin religion, is revealed to be one of sixteen Pieces of God in the broader universe of The Cosmere... one of whom already killed him and has set its sights on the rest of the planet. Dalinar has a Crisis of Faith when he learns.
- The cosmology of American Gods is established that everything mystical and otherworldy - gods, fairies, djinn, etc. - are all products of humanity's belief that they exist and grow powerful from acts of worship. The story is set in Turn of the Millennium, and by then The Old Gods, the gods worshipped in long-dead religions (also Jesus), are struggling in an America where the New Gods, gods of modern day concepts like technology and mass-media, have become the dominant force. All throughout the story, the protagonist Shadow encounters a Buffalo-Headed Man who is implied to be America itself, a being who is to gods as gods are to humans and has existed since before any of them walked its lands.
- An in-universe example occurs in Preacher (2016). God, in order to shirk His responsibilities, had Mark Harelik killed and sent to Heaven to serve as an actor who'd play the role of God so nobody would know He was missing. The actual God goes off to wander the Earth in a dalmatian suit.
- Supernatural zig-zags this with Chuck Shurley. While he is the legitimate God of the Supernatural universe, Season 11 reveals he is not the most powerful entity in it. Rather, the Anti-Goddess Amara/the Darkness is his Stronger Sibling, who required both God and the archangels to seal her away in the first place...though they ultimately prove equal in strength. Possibly played straight in Season 13, however, with the reveal that neither are the be all and end all with the introduction of the Cosmic Entity, a being of nothingness in charge of the Empty who predates both of them and neither of them have any authority in its domain.
- Gnosticism: The Demiurge is meant to represent the Old Testament God from The Bible, and is the creator of the physical universe. However, the physical universe is actually the lowest of realms, and he is ignorant to the fact he was created by Sophia, assuming he's the unsurpassed supreme deity. Sophia herself is the farthest aeon from the Monad, the real highest being.
- Classical Mythology: While Zeus is the Top God and treated as such in Ancient Greece, he isn't the most powerful deity (though he is close). Even he fears the power of Nemesis or her mother Nyx, primordial goddess of darkness. He (and the rest of the gods) are also subject to Ananke, the deity of fate, though these higher deities aren't worshipped.
- Asura's Wrath: The Eight Guardian Generals are specifically referred to as Demigods, and when Deus, their commander, betrays one of their kind, Asura, and uses him as a scapegoat to institute his One World Order, the following Written by the Winners history specifically calls the remaining demigods the "Seven Deities", with Deus as their leader. After Asura has finished murdering 5 of the 7, including Deus, converting one of them to his side in the process, not to mention beaten the snot out of the threat that the One World Order was supposed to combat, the remaining 7th deity takes his daughter hostage to use in her revenge.. and is then immediately and effortlessly killed by the actual God, Chakravatin, who reveals that The entire 12000 year plot, including all of the suffering perpetrated by the One World Order, was set in motion to choose an heir. Asura... doesn't take this well, and responds how a rage-powered demigod would.
- Played for Laughs in the Futurama Leela fights with a being who claims to be a god and is using his powers to rule over a primitive civilization. When she defeats him, he admits that he isn't a god, but an immortal alien with omnipotent abilities.
The Sun God: "You found me out... I'm not really a god... I'm just an ordinary...eternal, omniscient, superintelligent being."
- Mortal Kombat 4 introduces the Elder Gods as the most powerful deities in the Mortal Kombat universe, inattentive beings who set up the rules of kombat in the first place. Mortal Kombat: Deception ends up revealing that they fought and split up the real God figure, the One Being, into the different realms in the first place. And Mortal Kombat 11 implies he's merely a lesser threat to Kronika, who belongs to a race of Titans and holds control over timelines.
- Poseidon: Master of Atlantis: One mission has you run into Mayans, whose Top God is named "Hef" and is good at forging things. It's quickly revealed this is actually Hephaestus (who is nowhere near the Top God in the Greek pantheon), and revealing this causes him to attack you throughout the level.
- Shin Megami Tensei: YHVH is meant to represent the Abrahamic God, and as the supreme being of the Law philosophy is considered to be God (albeit malevolent). However he is actually the the Avatar of the Great Will, a Sentient Cosmic Force that created and rules over the multiverse.
- Xenoblade: Lady Meyneth and Zanza are the soul of Mechonis and Bionis are assumed to be the gods of the world. In reality, Alvis is revealed to be the true Monado and the true god of the Xenoblade universe.
- DarkMatter2525: In "God's God", Jeffrey chides Yahweh for being a Hypocrite over mocking atheists non-belief in a deity by pointing out that if He believes he doesn't have a creator, then He is an atheist as well. They end up killing each other and end up in The Afterafterlife, where Yahweh's God judges his actions with similar judgement he gave to non-believers. This leads to Yahweh complaining about unfair judgement, and Hilarity Ensues when the different Gods keep killing each other and going to higher afterlives until they're encountered by a man, who states he made up the gods and they fade out of existence.
- Family Guy: A comical inversion occurs in Boys Do Cry. It's revealed that the Devil is not the true threat to salvation. Rather it's the Super Devil, who rides a motorcycle and holds a jar of marmalade that forces people to commit adultery.
- Futurama: Discussed in "Godfellas" with the Galactic Entity. When Bender encounters it he wonders if the being is God, but wonders if he is actually the result of a space probe that collided with God. The Galactic Entity says "perhaps", and it's left ambiguous on whether it is God or a god-like entity.