The Magic Eater is Exactly What It Says on the Tin: a character that feeds on magic and/or magic users. If the main character(s) use magic, then the Magic Eater will present a clear threat to them. If Pure Magic Being exists, the Magic Eater may try to prey on them.
Often, eating magic allows them to nullify spells or use them themselves. In some cases, a Magic Eater will from simply eating magical energies to being a full Mage-Hunting Monster. See also Phlebotinum Muncher, especially when it's Munching a Sci-Fi element rather than magic. Overlap with Fantastic Vermin is common, especially when magic-eating creatures are common and relatively weak individually, making them more of an irritating nuisance than a true threat.
Examples of this trope include:
- Black Clover: This is the true form of Charmy Pappitson, after awakening her half-dwarf heritage and Food Magic. In this form, her sheep familiar transforms into a wolf that can quite literally eat any magic in the area and transform its mana into Super-Strength for Charmy's own body.
- Fairy Tail has Acnologia one of the most dangerous beings in the setting. Acnologia is a Dragon Slayer, a wizard who can empower themselves by eating a certain element. Acnologia's "element" is magic, which makes him all-powerful in a setting where society has built itself upon magic and its use.
- Little Witch Academia (2013): The Briton Red Dragon is shown to be this, as it grows in strength and power by absorbing any kind of magic, which becomes a problem after a bunch of students attempt to attack the dragon by using magic after it escaped, not realizing that they're only powering it up until it was too late. The only magic that is shown to be effective against the beast is the Shiny Rod's magic, which is how Akko was able to defeat it.
- Magic: The Gathering: The Manaplasm is a Blob Monster that feeds on spells; mechanically, it gets a power and toughness boost when its controller casts a spell equal to that spell's mana cost.
Urak froze when he heard it. That was his first mistake. He turned and cast a dramatic ward spell. That was his last.
- Like Father, Like Daughter: A type of lizard found in Hekapoo's dimension can absorb magic to grow larger, and seems to prefer magical creatures as prey.
- Natural Histories: The oaks that grew over the ruins of Everfree learned to consume the magic that permeated the ruins of the old Equestrian capital, absorbing it and making themselves strong. It allowed them to overwhelm the other trees of the forest but also changed them, turning them dark and twisted and causing the forest to become the wild, haunted and terrible Everfree Forest of canon.
- survival is a talent: House elves used to subsist on ambient magic in the environment, but now that there are fewer magical forests in existence they survive by binding themselves to magically powerful families. They are being paid, in a way, though the system is far from ideal for either half of the arrangement; house elves are vulnerable to abuse by their masters, and wizards cannot use their own magic to protect themselves should a house elf turn on them.
- The Avatar Chronicles: In Epic, Ragnok owns a shield holding a magic-eating demon that consumes the enchantments of any weapon it touches.
- The Cosmere: There are a number of types of being that eat Investiture, the generic term for magical power across the worlds.
- Elantris: Elantrians are humans who have undergone a supernatural Metamorphosis that grants them agelessness, Geometric Magic, and the ability to consume investiture instead of food. They ordinarily draw it from their homeland's Background Magic Field, but need to bring reserves along if they travel offworld.
- The spirits of objects in the Cognitive Realm need a source of investiture to sustain themselves when they're travelling far from their physical bodies.
- Warbreaker: The Returned are sent back from death with idealized bodies and supernatural abilities, but need to consume investiture every week to survive. This poses a bit of a problem, since the only local source is part of the Anatomy of the Soul. One Returned ends up on The Stormlight Archive's planet Roshar instead, where investiture literally rains from the sky.
- The Stormlight Archive: Larkins are fantastically rare but otherwise unremarkable crustaceans that feeds on stormlight, which they can suck out of the gems used to store it, Shardplate Powered Armor, or surgebinders who use the stormlight to fuel their magic — which can be a nasty surprise for the surgebinder.
- Counselors and Kings: The laraken is a demonic monster which consumes any magical energy in its vicinity, making it impossible to defeat through magical means — and as it lives in The Magocracy of Halruaa, whose people almost never consider doing something without magic, it's fed quite well on the countless foolhardy adventurers who've thrown themselves at it over the centuries. It's ultimately revealed to have been a creation of the legendary necromancer Akhlaur, who can drain stolen magic out of the laraken and use it to refuel his own powers at will — leaving the creature in a near perpetual state of starvation no matter how much it gorges itself. Akhlaur himself, of course, is immune to the laraken's powers.
- Enchanted Forest Chronicles: Discussed and averted. In Searching For Dragons, someone destroys a large section of the Enchanted Forest, and left a few dragon scales at the scene to implicate the dragons. King Mendanbar notes that the ambient magic in the area is also gone, and wonders if dragons eat magic. Some research shows they don't, proving the dragons weren't responsible. It turns out the wizards, using magic-absorbing staves, are the cause.
- Guards! Guards!: Noble dragons, in order to sustain their impossible natures, live on magic — how else can such a creature even fly, or breathe fire without scorching off its own lips, or breathe fire at all? They were common when magic was as well, but then the magic went away and so did they. The cultists originally summon for brief periods though the magic of small enchanted objects, which crumble into ash once depleted, but the beast secures a more solid foothold in reality by absorbing magic from the library of the Unseen University of the wizards.
Lady Sybil: But it looks real enough. I mean, you'd expect a magical creature to be, well, gauzy.
Vimes: Oh, it's real. It's real all right. But supposing it needs magic like we need... sunlight? Or food?
Lady Sybil: It's a thaumivore, you mean?
Vimes: I just think it eats magic, that's all.
- Heralds of Valdemar: the third book of the Mage Wars Trilogy, The Silver Gryphon, introduces a mutant strain of creatures called Wyrsa. Though smaller than their base line cousins, they're far more cooperative and, as Tadrith and Silverblade discover, eat magic. This is a particularly big problem for Tad as gryphons are magical in nature and require it for their bodily functions, especially since a large enough wyrsa pack only has to be in the general area to leech magic (as shown when the duo's magical fire starter and tent both fail). Even the arrival of Skandrannon and Amberdrake only serve to whet the creatures' appetites and Amberdrake points out that if the mutants aren't dealt with now, no magical creature will be safe. Fortunately the pack's voraciousness is used against them by planting magic bait under a rock slide and killing them all.
- Moongobble and Me: Book 5 features the Dangly-Boo, which eats magic. Fortunately for Snelly the Mischief Monster, it also eats half the magic that cursed her to look like a beautiful woman, causing her to turn mostly back to normal. Later, after he's feeling better, he eats the rest of the curse, restoring her to normal. Later, he eats the were-toad curse off the Old Woman of the Forest of Night, achieving what she wanted all along (though not in the way she intended). After the book's quest is dealt with, it comes back home with Moongobble to help him with his spells — he'll cast one, it'll eat the spell, and then suggest ways to improve it.
- Rivers of London: Ghosts feed on magic, becoming more solid and apparently feeling better when they're near a source of it. In The Furthest Station, Peter and Nightingale fill a stone with magic which acts as a sort of ghostly soup kitchen, and the spirits are described as streching their arms to it as though warming them on a fire. It's also been suggested that Life Drinkers may actually be eating magic, since they're kind of the same thing.
- The Scholomance: "Mals" are a hugely varied class of monster that form out of magic and are drawn to wizards to consume their Mana — usually along with their flesh.
- Tales From Verania: The main villain of the second, third, and fourth books has the ability to consume a wizard's magic, a feat that kills the victim and is akin to devouring someone's life force.
- Kamen Rider Wizard: Kamen Rider Beast draws his power from the Chimera Phantom sealed inside his Transformation Trinket, and will die unless he keeps it fed on the Mana of Phantoms he defeats. Whereas Wizard's catchphrase when entering battle is "It's Show Time!", Beast's is "It's Lunch Time!". While this makes Beast less powerful than spellcasters with their own mana like Wizard, late in the series it allows him to act as a Spanner in the Works: Since Wiseman can't use Beast as a mana battery for his Ritual Magic, he captures the other wizards but simply beats up Beast and leaves him to die. Beast then shatters his Transformation Trinket, freeing Chimera who proceeds to eat Wiseman's spell before it's complete.
- Mahou Sentai Magiranger/Power Rangers Mystic Force: The Big Bad N Ma/Octomus the Master is capable of eating magic, making him a fitting threat for a mystical setting where magic is the source of the Rangers' powers. The heroes manage to defeat him by firing an endless beam of magic down his throat, it being too much for his evil appetite.
Octomus: I have... devoured... all... I CAN! (Explodes into nothing)
- Wizards vs. Aliens: The Nekross have devoured the magic from the rest of the universe, and are now on Earth to finish the job. And, of course, they'll just suck up any spells that you try and throw at them.
- Dungeons & Dragons:
- Beholders, as explained in the Lords of Madness supplement, are a downplayed example of this trope. Each beholder has specialized "evocularies" in its central eye connected to "dweomerlobes" in its brain, which power its eye-stalks' spell-like abilities by absorbing magic by viewing it through its main eye (the same one that can generate a cone of Anti-Magic). The actual magic drained from looking at something like a scroll or wand is minuscule, and it would take extended viewing to drain the item to uselessness, but beholders get more benefit from examining new and different magic items. Which handily explains why a creature with no limbs would have bracers of archery and winged boots in its treasure hoard
- The 4th edition added upgraded versions of rust monsters, known as Dweomer Eaters, which eat magic items rather than just metal items.
- Gauths, a type of lesser beholderkin, feed on the magic of enchanted objects. One of their eye beams allows them to do this in combat, draining one charge at a time from magical items or, for permanently enchanted ones, rendering them useless for a round. They can also swallow magical items, where items with charges lose one per round and permanently magical ones are drained over a day; the items are spat back out once the gauth has sucked them dry. They cannot, however, drain magic or spells from living creatures. They can live fine on meat, but prefer to eat magic.
- Disenchanters are blue, camel-like creatures that disenchant magical items to feed on the magic energy. They are somewhat infamous for their tendency to disenchant items the Dungeon Master feels are unbalancing the game.
- Magebanes are batlike creatures that feed on magic they siphon from spells, and tend to follow wizards around in order to have a reliable source of food. This is a problem for wizards, as the magebane's feeding tends to depower or even nullify spells. Getting rid of one is easier said than done, especially since only the affected spellcaster can see it, but one way to do it is to cross paths with a more powerful wizard; the magebane will recognize them as a superior source of food and make itself their problem instead.
- Magerippers are tiny, swarming pests that feed off of the magical power of living beings. They're a particularly danger to spellcasters and magical beings, as they'll swarm them aggressively and siphon off their prepared spells one after the other. They also gain temporary hit dice if they successfully dispel ongoing magical effects. They can't feed this way on magic objects, but still tend to crowd around them in frustrated confusion until a better food source presents itself.
- Arcane ozes can siphon arcane spells. Any arcane spellcaster within sixty feet of an arcane ooze has to make a saving throw each round or lose one of their highest-level spells as the creature absorbs its magical energy, gaining temporary hit points from the effect.
- Planescape: Incantifers are former members of the Incanterium faction who became obsessed with the pursuit of magic. Modern Incantifers no longer need to eat, drink or sleep, but instead subsist entirely on magic and and must feed on energy from spells and magic items in order to survive.
- Xaren eat enchanted metal.
- Hunter: The Vigil: Agonizers are extradimensional insects that feed on magic. Their normal modus operandi is to enter a human body, burrow into the brain, and extend nerve fibers through the body so as to puppet their host and use it to reach magic-rich areas; most, however, end up dying due to scarcity of magic-rich areas on Earth. Cheiron researchers have worked out that, if the agonizer's nerve fibers are trimmed and anchored to metal spikes and the whole thing is implanted in a hunter's arm, the host gains the benefits of magic draining without losing control of their body. The implanted magic bug feeds when the hunter extends the spikes out of her hands and uses them against magical beings, allowing the symbiote to feed in a process that's agonizing for the victim. However, agonizers are still capable of making their host's life very unpleasant if left to go hungry.
- Mage: The Awakening: The Timori Legacy have built Black Magic into their souls to feed on other mages. They start by stealing Mana to prolong their lives; the strongest can De-power mages entirely to halt their aging or use their stolen magic. Some even "farm" captive mages until their minds break from the strain.
- Midnight (2003):
- Aryth for Izrador feeds on magic that he siphons through the Black Mirrors. His ultimate goal is to drain all the magic in the world, shatter the veil, and return to heaven to pick up the war he left off.
- Disenchanters are camel-like creatures that consume the magic within artifacts, stripping them of their supernatural qualities as they do so.
- Spellvoids are a variant of Will-o'-the-Wisp that, instead of feeding on emotions, feeds on the magical potential of living spellcasters, disrupting their ability to work magic.
- Ponyfinder: The flutterponies descend from the flutters, insect-like fey that fed on magic and descended in swarms to devour any source of it that they could find, including living beings.
- Shadowrun: Nimue's salamanders can absorb the magic of active spellcasting, preventing the spell from manifesting and using the energy to boost their own powers. There have been attempts to train them as anti-magic security, but these have been hampered by the difficulty in getting them to feed only on specific sources of magic instead of anything in range and in keeping them from leaving when an area's dry of magic.
- Warhammer: Age of Sigmar:
- Vulchares are twisted avian creatures gifted to some Kairic Acolytes of the Arcanite Cults. These arcane birds have an insatiable hunger for magical energy, using their razor sharp claws and beaks to rip it from the bodies of enemy wizards if necessary.
- Those daemons with the greatest hunger for magical energy often group together into Aether-eater Hosts. These Hosts seek out and set upon enemy spellcasters so that they can leach their magical energies to revitalize their own material bodies.
- AdventureQuest Worlds: Belrot the Fiend is a demon summoned by the Grand Inquisitor in the Citadel questline for the purpose of draining and devouring the magic of the land, which he utterly hates.
- Baldur's Gate III: Gale, a Gentleman Wizard who joins your party, has a peculiar condition that requires that he absorb the power from magical artefacts on a regular basis, or else there will be terrible consequences. This is because he has a Netherese Orb embedded in his body, and he needs the power from artefacts to keep it stabilized: otherwise, this Fantastic Nuke in his body will go off, killing everyone and destroying everything in a massive radius. He can have his condition stabilized on a longer-term basis under two conditions: giving him items to keep him stable until Elminster can stabilize it on the goddess Mystra's behalf, so that he can use it manually to destroy the Absolute; or deprive him of artefacts until he is desperate enough to make a bargain with Raphael.
- Final Fantasy XIV: In order to exist in corporeal form, the Primals continuously syphon aether from the world around them. Because everything is comprised of aether, this continuous drain on the land destabilizes it, making Primals into Walking Wastelands.
- The Voidsent also feed on aether, though usually on a much smaller scale.
- Guild Wars 2:
- Elder Dragons are assumed to consume magic, and are as old as it, resulting in some thinking magic to be a limited resource. The fact that they do consume it is eventually confirmed, with Walking Spoiler Mordremoth being seen consuming magic from disrupted ley lines. Living Worlds Season 3 reveals that typically the Elder Dragons each consume only the portion of magic in leylines attuned to their nature. When an Elder Dragon dies, the others can devour its essence and begin feeding on that portion of magic as well, becoming even more dangerous as a result.
- Skyscales are a species of lesser dragons born when Kralkatorrik tore through the Mists. They also feed on magic, although to a far lesser degree.
- League of Legends has Galio the Colossus, a giant, gargoyle-shaped bulwark designed by the kingdom of Demacia, made out of an Anti-Magic mineral called petricite. He was originally meant to just be a tower to ward off foreign armies by eating their magic, but an unexpected (and possibly intentional) result of his design is that this causes him to come to life, allowing him to smash the armies on his own. In gameplay, he's generally a very sturdy Mighty Glacier, but he gets even greater benefit out of nullifying magic-users.
- Nexus Clash: The Corruptor demon has Magic Eater powers as their signature trait. So great is the Corruptor's magic-absorbing ability that aiming a magical gun at one and missing is sometimes enough to forfeit the gun's magical attributes to the demon.
- Warcraft III: Reign of Chaos: The Undead Destroyer does this with its signature abilities, Absorb Mana and Devour Magic. Since the Destroyer can't regenerate mana naturally, it eats it from other units, with the former spell taking a friendly unit's mana and the latter dispelling all buffs and debuffs in an area and giving the Destroyer mana and health for each.
- The felhounds of the Burning Legion were portrayed this way in the War of the Ancients trilogy of novels. They existed to seek out enemies with magical power and would drain them until their bodies were nothing more than dried husks. Although this threat almost immediately underwent a form of The Worf Effect, as part of Azshara's characterization was showing that, despite being one of the most powerful magic users in history and thus their ultimate food, she could have the felhounds behaving like puppies in her presence.
- Elves tend to be this generally, but Downplayed. The Highborne elves drank from the Well of Eternity, a massive source of magic in the world. When that source was destroyed and the elf cultures broke apart, each group found their own substitute — such as the Night Elves' moonwells or the High Elves' Sunwell — because not consuming some form of magic would put them in withdrawal and turn them into mindless beasts. This fact is most obvious with the Blood Elves in Burning Crusade and the Highborne Elves in Legion. The destruction of the Sunwell by the Scourge became a major problem for the High Elves and their Blood Elf descendants, as it left them desperate for new sources of arcane energy.
- Nomad of Nowhere: The crown of El Rey eats magic users to sustain its own power.
- El Goonish Shive: There are interdimensional whale-like creatures who feed on excess ambient magic.
- Val and Isaac: These are briefly mentioned to exist. To deal with them, the Black Magic-wielding mercenary Space Dread simply stocks up non-magic weapons from a friend's family forge that specializes in such goods.
- Codex Inversus:
- Manticorats are rodents that have adapted to feed primarily on magic and magical creatures. Their normal food source are spellcasting insects, such as conjuring ants and illusionist butterflies, but they are a serious pest for wizards because they will happily gnaw on wands, eat reagents, drink potions, and chew through scrolls. Keeping them out is almost impossible, since they will simply nibble holes through shields and wards and lick off repulsive enchantments.
- Capibangels are larger relatives of manticorats that live in the Olympus Crater, one of the most magically active areas in the world. The ambient magic is so high there that they barely need to move at all, and instead can just "chew" the air and consume the magical energy there.
- Aladdin: The Series: In his debut episode, Mozenrath summons a magic eater from Another Dimension, the Thirdac, to Earth with the intent of using it to conquer the world by weakening any and all magical defenses he encounters. To prevent the creature from attacking him, he kidnaps Genie and forces Aladdin and co. to help him place a control collar on the Thirdac to save Genie's life. Naturally, Aladdin turns the tables on Mozenrath, via Iago, and sets the Thirdac on him, forcing him to send it back to its world to avoid being eaten himself. It's also shown that the Thirdac is no threat to non-magical beings, as Aladdin beats it into the ground with his bare hands.
- Fangbone!: In "The Bill of Magic", Venomous Drool sends such a creature to attack Bill after he gains the ability to cast spells from exposure to the Toe's magic. Its a tiny white thing identified as a Voidsnarl, and while Fangbone initially laughs at the sight of it, it's shown to be no joke as it vacuums up magic through its orifices, and even Drool is so terrified of it that he cages it up using special restraints to release it.
- He-Man and the Masters of the Universe (2021): Gary the Dragonfly was mutated by the Power of Havoc into a giant creature with a Horror Hunger for mystical power. His hunger was sated when he ate an Artifact of Doom powered by Havoc, but the Masters of the Universe and the Dark Masters were both after said artifact. After getting it back, Sorceress sends Gary to the Mystic Mountains, a land where everything is infused with magic, to sate his hunger and end his threat.
- My Little Pony: Friendship Is Magic: Lord Tirek can drain and consume magic and gain its effects. Considering all ponies' abilities in this setting are magical in some way (at one point he drains an entire squad of Pegasi and they lose their ability to fly), this makes him a very serious threat once he drains enough, especially since he's even able to drain the magic of Discord, a Reality Warper Physical God. A later appearance has him reveal he can only consume the magic of living things, however, which presents an issue since he can't just drain the energy maintaining a forcefield around the Bewitching Bell and so he needs to "borrow" the magic of one his allies to get strong enough and brute-force it open. He also reveals he can give back magic he's eaten, which is visually represented by him throwing it up.
- The Owl House:
- Basilisks are a supposedly extinct species that can drain the magic of witches and demons, though eating Luz's glyphs causes them physical pain. "Yesterday's Lie" reveals that the species was actually revived by the Emperor's Coven specifically to study this ability and that it merely fuels their other magical abilities like shapeshifting rather than being needed for sustenance. It's also shown that they're also able to get magic from enchanted objects (like Eda's discarded Hexas Hold'em deck).
- In his debut episode, Emperor Belos is shown to not be in the best of health. He recovers by cracking open a Palisman (which are sapient entities) and absorbing the magic bile inside it through his eyes.