Summon Bigger Fish

""Sometimes the best way to deal with a mad man is to send in another madman...""

- Angry Joe, Kickassia

Of course there is Always a Bigger Fish, but sometimes they aren't willing to just pop up out of nowhere and get you out of the current mess. That's where this trope comes in. Summon Bigger Fish is when you get another monster/god/whatever to fight the current one, and hope once the smoke is cleared the one you just called will leave you alone, or at least be weakened enough by the fight to be taken out with less insane tactics. Sadly, the odds that doing this only makes things worse is actually almost 50/50 -- Evil Is Not a Toy, after all—but then again, once you've crossed the Godzilla Threshold, anything is a viable option.

Compare Mons.

Remember, this has to be a conscious use of getting another monster. If it appears by accident, or by the monster's own choice, put that example in Always a Bigger Fish instead.

Named for a Running Gag in Darths and Droids.

Compare Awakening the Sleeping Giant, Did You Just Punch Out Cthulhu?, Let's You and Him Fight, Enemy Mine.

Anime & Manga

 * It doesn't seem that way in Neon Genesis Evangelion until it turns out that.
 * In Higurashi no Naku Koro ni the heroes eventually need to.
 * In Slayers, Lina calls on power from Shabranigdo, the God of Evil, to defeat lesser monsters. Twice Lina calls on power from the Lord Of Nightmares.  She's just that badass.
 * A definite example in Naruto is Manda, the giant snake. Orochimaru and Kabuto summon him to fight Jiraiya and Tsunade, but these summons have a tendency to be rather unreliable, and Manda is by far the worst, once demanding 100 human sacrifices to pay for his service. Especially considering, they were desperately hoping he didn't betray them anyway. Ultimately,
 * in Dragon Ball, Vegeta's still powerful enough to kill Goku, Krillin, Gohan and Yajirobe even after all the unGodly punishment he took in the climactic battle of the Saiyan saga. In a desperate gambit, Goku tells Gohan to look at the Power Ball in the sky, which transforms him into a raging, uncontrollable giant were-ape (oozaru). Initially, having lost all reason, Oozaru Gohan presents just as much of a threat to the heroes as Vegeta does, but Goku is able to telepathically communicate with him, and sics him on Vegeta.
 * In an early episode of Pokémon (The Ghost of Maiden's Peak), when Ash attempts to fight a Gastly using his Squirtle and Bulbasaur. The Gastly summons an illusion of Blastoise and Venusaur, and then goes so far as to combine them into Venustoise, turning his already bigger fishes into one sort of... biggerer fish.
 * Its explained that the pre-evolved forms fear their fully evolved forms to an extent due to some kind of instinct. So making them bigger and more badass is going to cause them to panic.
 * Digimon Adventure had Tai force Greymon to evolve to defeat an opponent Greymon, resulting in SkullGreymon. Said SkullGreymon proceeds to kill the Greymon and run wild, blowing stuff up and curbstomping the other partner Digimon's attempts to restrain it.
 * In Digimon Tamers, Takato orders Guilmon, both enraged by the murder of, to evolve to the Ultimate form in order to revenge-kill Beelzemon. The result is Megidramon, whose very existence threatens to cause the Digital World to collapse... and Beelzemon thrashes him anyway.
 * The fight between Marcus and in Digimon Savers, when, has their partners ShineGreymon and  roughly equal in strength, and so an attempt by Marcus to invoke the more powerful Burst Mode is influenced by his rage at ; this results in ShineGreymon Ruin Mode, who runs wild before reverting to a DigiEgg;  are forced to retreat.
 * In Hellsing we have the enslaved vampire Alucard who works for the Hellsing organisation hunting vampires. Since all vampires are a universally psychopathic, obsessive race who commit slaughter for fun and are almost unstoppable to a regular human, Alucard is no exception, except he has the power of a Physical God, and there is literally nothing that can stop him, with very few exceptions. In OVA III, he gladly shreds a small army of innocent police officers because they (correctly) thought that he was an insane serial killer. The only thing that differentiates him from a far more dangerous version of what Hellsing is fighting is that he's honour-bound to serve Integra, his master.
 * The World Government in One Piece get it in their heads that the only way to compete with the power held by the big wig pirates in the new world is to enlist the Seven Warlords of the Sea, who are essentially government sanctioned pirates, to fight for their side. So essentially, they're privateers. If you'll recall many of the most famous pirates started out privateers and then were retconned into pirates by the governments withdrawing support. In One Piece, that happened backwards.
 * Quent in Wolfs Rain fights wolves with Blue... Who's a wolf. Well, half-wolf half-dog, but she looks exactly like one. To be fair, he also uses a shotgun.
 * Yumi in Magical Idol Pastel Yumi stops a swarm of bees by creating a giant bee.

Comic Books

 * When he's not being used as a villain, this is the major role played by Marvel Comics character Galactus—the Fantastic Four have summoned him to defeat cosmic villains like the Sphinx, his rogue herald Terrax, Hyperstorm, and Abraxas, and various space-based franchises have used the character for this as well.
 * Reed Richards has also been called out on this a few times, most notably being put on trial by an alien civilization.
 * Similarly, DC Comics often shows lesser superheroes calling on the Spectre when mystical evils get way out of hand. In most modern versions of the Justice Society of America, this is essentially the Spectre's role on the team.
 * Used in the Legion of Super-Heroes V3 comics. The Time Trapper is, among other things, the Anthropomorphic Personification of the theory that the universe only goes 'round once. There's another villain, the Infinite Man, who is the embodiment of the theory that the universe runs on an infinite loop. Brainiac 5 brought in the latter to defeat the former.
 * In Blackest Night, when faced with a Black Lantern version of The Spectre, the heroes come up with the really desperate plan to sic Parallax on him (using Hal Jordan as his host once again).
 * Earlier, the Green Lanterns on Oa are overwhelmed by a Black Lantern swarm, so Guy Gardner decides to release a Red Lantern from the Oan prison and throw it at them. This works for about three panels before the Alpha Lanterns kill the Red Lantern for "escaping". And then the red ring goes after Guy.
 * In Hellblazer's All His Engines, John Constantine is charged with killing several demons. He succeeds by feeding them to an Aztec god.
 * Similarly, an early arc has a cult succeed in summoning a truly ancient dragon-god by creating a lesser fear-deity. In this case, the dragon-god summons itself to eat the lesser god.
 * John must really like this strategy. In the Dangerous Habits story arc, he's already pissed off the First of the Fallen, who's waiting for him to die of cancer, so John summons two other Lords of Hell and . Which leads to an early CMOA for Johnny, as he gets to flip off all three of them and walk away smiling.
 * In the Season 8 comic-book continuation of Buffy the Vampire Slayer, Buffy and her slayers are depowered and must fight against the US Army. When all hope seems lost, Buffy summons the goddesses they had previously given their power to in a (ultimately vain) attempt to hide. The goal is two-fold: to have the ginormous goddesses attack the army, and to get their powers back. The plan backfires, however, as not only do the slayers not get their power back, but the goddesses attack both group indiscriminately. Buffy is finally able to defeat the goddesses after gaining Superman-like powers.
 * In one episode of De Rode Ridder (The Red Knight), goddess of light Galaxa does away with god of darkness Bhaal by summoning what is hinted to be Satan himself. (Yes, De Rode Ridder is that much of a Fantasy Kitchen Sink.)
 * During the DC's Our World At War storyline, in order help defeat the forces of Imperiex, Doomsday is released from the can Superman had sealed him in.

Fan Works

 * Godzilla vs Cthulhu is a clear example.
 * Nobody Dies gives us Cthulhu vs ADAM.
 * The Unity Saga contains an example, when
 * Luminosity has Bella do this to establish her as a Guile Heroine. James is going to kill her, but has enough flair for the dramatic to leave her alive long enough to talk. She convinces him to take her to the Volturi, who rule vampires and don't like being disturbed.

Film
""Send a maniac to catch a maniac.""
 * Clash of the Titans, as well as the legend of Perseus, was him using Medusa's head to defeat the kraken.
 * Although in the original Greek myths, it's a sea serpent (kraken are from Germanic/Norse myth and legend—they're in the movie because of Rule of Cool).
 * then again, it really isnt a Kraken either, just . they probably just liked the name.
 * The film The Lord of the Rings: The Return of the King has the capital city of Gondor under attack by a Badass Army of evil orcs and trolls. Fortunately for the good guys, Aragorn gets an Army of the Dead to come to the rescue. Given that there's no way to defeat the undead, some consider this a Deus Ex Machina outcome.
 * Perhaps when the heroes teleport the giant rock monster onto the enemy starship in Galaxy Quest?
 * Essentially the plot of Monsters vs. Aliens.
 * Arguably the tactic employed in the Pirates of the Caribbean films, when Calypso is summoned in hopes that she'll take out the East India Trading Company and Davy Jones.
 * The film Godzilla: Final Wars pretty much uses this trope as its basic plot. Long story short-humans release Godzilla from imprisonment so he can fight the other giant monsters so that the humans can stop the evil aliens from destroying the world.
 * To be more specific, Godzilla didn't care about fighting the aliens, he was just chasing after a flying submarine/battleship that he fought before getting buried in a glacier, the humans knew he would follow it so they just lured him into where the other monsters were.
 * Quite a few of the Godzilla films had plots based on this trope. Godzilla vs King Ghidorah did it twice: the humans release Godzilla to deal with Ghidorah, then Mecha-Ghidrah to deal with Godzilla.
 * Mal and his crew  to take on the Alliance in Serenity..
 * Though in the end the Alliance win, making this more of a "Summon smaller fish" or "Summon distraction".
 * And given that Mal makes the case that the Alliance has to clean up its own mess.
 * The title character in Constantine summons Lucifer to defeat Mammon and Gabriel.
 * At the end of A Bugs Life, Flik actually summons the very bird that attacked him earlier in the film to
 * The future San Angelenos in Demolition Man view the release of John Spartan like this. To them he's just as much a criminal as Simon Phoenix and his worldview and behavior is just as alien.

"Aereon: In normal times, evil would be fought by good. But in times like these, well, it should be fought by another kind of evil."
 * Boa vs. Python: Send a giant snake to kill a giant snake. For some reason. Apparently the plot doesn't make terribly much sense.
 * Pretty much the plot of The Chronicles of Riddick. The Necromongers, a strange cult of Omnicidal Maniacs, is threatening the Galaxy. What do the good guys do in response? Track down convicted killer Richard B. Riddick in the hopes that he'll take care of them.

Literature

 * Daine attempts this in Wild Magic with an enormous kraken. Despite her apprehensions, it works out pretty well.
 * To clarify: Daine summoned it knowing that she wouldn't be able to send it away again - it's too powerful and - more importantly - too intelligent to be fully controlled by her wild magic. However, she took a calculated risk, keeping in mind that she had a pair of seriously overpowered magical allies, who were merely out of the game for a while. Sure enough, once they've recovered, they're able to 'convince' the Kraken to go home again.
 * At the end of Watership Down, the protagonist rabbits.
 * The Dresden Files: At the end of Dead Beat, Harry is facing down a bunch of necromancers and an army of zombies. His solution?
 * Bonus points because, even though there are strict rules forbidding the spirit of his solution, they only apply when such spells are cast on humans.
 * Same author, different series: In the final book of the Codex Alera, Tavi has to find a way to deal with the insanely dangerous Vord Queen, while at the same time she's putting a lot of effort into dealing with him. He just plain old can't face her head-on. So he Chaos ensues.
 * In the Discworld book Guards Guards, after  loses control of the dragon he summoned, Vimes encounters him planning to summon another one to fight it. (He's about 90% insane by then.)
 * This done with confidence tricksters is essentially the plot of Going Postal, where Vetinari uses Moist von Lipwig to work against Reacher Gilt. In this case his insurance is that Good Feels Good and by the time it's over Moist will have reformed sufficiently to no longer be a problem.
 * Also referred to in Making Money, where Moist explains that the mongooses were bred in the postboxes, to keep down the snakes; who were introduced to reduce the number of toads; which were put there to keep down the snails. The snails had gotten in on their own accord to eat the glue on the stamps, though. He admits that they "were a bit too creative in our thinking" though.
 * Near the end of Shiver, the protagonists determine that lycanthropy may be curable through  They attempt to do this by   Results?
 * Used in one Cthulhu Mythos story. The protagonists in the story are investigating a series of unusual events, the cause of which turns out to be an avatar of Nyarlathotep. They find some notes left by a professor with experience in the mythos that came to the place before them and was killed. The notes contain instructions on how to perform a ritual to summon the Great Old One Cthugha, so that the two beings (who apparently don't like eachother) will fight, resulting in both being banished. The notes also suggest that as soon as the ritual is complete, everybody should get at least several miles away from the site.
 * In Harry Potter, Hermione Granger does this by bringing Dolores Umbridge into part of the Forbidden Forest where the centaurs live. She hopes to trigger Umbridge's hatred of "half-breeds", which will enrage the centaurs and get them to take care of Umbridge for her. It sort of works.
 * When the centaurs are about to turn on Harry and Hermione, Grawp appears, looking for Hagrid, and gets into a fight with the centaurs, allowing Harry and Hermione to escape.
 * In Stanislaw Lem's The Tale of the Computer That Fought a Dragon, a robot king accidentally makes a robot dragon; he gets his battle computer to get rid of it—which, of course, it does by making larger and larger robot dragons. Eventually the computer tries to turn itself into an electrosaur and rule the planet, but the king hits it with his slippers and it accidentally turns itself into electrosauce. So Yeah.
 * This is the basis for Hiccup's Fiendishly Clever Plan in How to Train Your Dragon.
 * In Welkin Weasels: Gaslight Geezers, Maudlin accidentally acquires a magical ocarina which summons a demon if played and can't be thrown away or destroyed, but can only be passed on to another owner. Naturally, he decides to simply not play it. However, he and Scruff are later attacked by the dreaded manless horsehead (the ghostly head of a riderless horse) and use the ocarina to summon the demon to fight it while they run. Later, when they're captured and enslaved at an ironworks, Scruff manages to trick the overseer into taking and playing the ocarina, summoning the demon, which eats the guards (who are mink, and therefore larger and better prey than the weasel slaves, who escape).
 * Used twice in The Heritage of Shannara.
 * Druid: Being hunted by a gigantic cyborg spider? Drop it down a pit.
 * Talismans: Being attacked by several smaller, but still huge and tough, magical cyborg spiders? Lure them into the Mist Marsh, where they can piss off the huger and tougher tentacled horrors within.
 * In the Wizard of Rondo, after the protagonists have learned that It is not amused.
 * Arguably, this is what Moses does in the book of Exodus in the Bible when he calls down plagues upon Egypt.
 * The main premise of Forgotten Gods. The characters ask the Fair Folk for help, and it goes horribly right.

Live-Action TV
"You really believe you can handle that kind of horsepower? You're delusional! They'll both mash us like peas."
 * Primeval has what has to be one of the most epic uses of this trope: Lester is chased by a future predator. He can't defeat it, so he manages to make his way back to the main room of the ARC and tells Leek, who's commanding it, that since he won't beg for his life, Leek may as well just kill him now. Unknown to Leek, Lester opened the door to the cage holding a giant freaking mammoth. Said mammoth does not like the future predator. Said mammoth kills the future predator with extreme prejudice.
 * Played by the villain Crustaceans in the final episodes of Big Bad Beetleborgs. In response to the Beetleborgs finally acquiring the giant Roboborg, the Crustaceans respond by creating the equally giant Boron.
 * Babylon 5: When the Vorlons aim to destroy a planet with a population of six billion, Captain Sheridan, who knows too well that his fleet cannot take them on and win, summons a fleet of ships belonging to the other "First Ones", who then proceed to destroy the Vorlon planet killer.
 * The problem for the younger races was that they simply don't have the firepower to take out something so big (conservative estimates put the length at about 26 miles).
 * In the Season 7 Supernatural premiere, the Winchesters and Bobby summon Death to deal with . Subverted, though, in that . The potential danger of doing this is beautifully lampshaded by Crowley:


 * On one Saturday Night Live sketch Ben Stiller and Tim Meadows play small-town politicians in a series of dueling campaign ads on the topic of "the bat problem," (bat attacks on the citizenry.) The competing candidates advocate such solutions as soldier monkeys, erupting a volcano under the bat cave, and getting larger and more aggressive bats to eat the bats.
 * Doctor Who's titular Doctor tries this in "Ghost Light", and gets in really bad trouble.
 * To clarify: the enemy at this point is a Human Alien with some hypnotised human minions. The Doctor unleashes a mad angel.
 * An inversion occurs in Star Trek: Voyager when the Borg ask for Janeway's help in eliminating Species 8472.

Music

 * The children's song "The Old Woman Who Swallowed a Fly", wherein the woman in question keeps swallowing bigger and bigger animals to catch the one she swallowed before. Ultimately,

Multi-media

 * Kongu did this in Bionicle, during the Pit story. He used his Mask of Summoning to summon a giant Eldritch Abomination-style Rahi to kill a 300-foot Matoran-eating Eel. It was an interesting battle. This is pretty much Kongu's mask power, to summon monsters ... the only problem is he doesn't get to control the monster ... nor can he choose what monster arrives.
 * And this ends up biting him and the other Toa in the ass later on, as the Rahi and the Eel team up with each other and the mutated Gadunka during the Melee a Trois at the end of that arc.

Mythology

 * In Assyrian and Babylonian mythology Pazuzu was a Chaotic Evil wind demon who brought drought and storms. However, pregnant mothers often invoked him with amulets to ward off his enemy and, in some versions, wife, Lamashtu, who killed children in childbirth and kidnapped newborns.
 * In Egyptian mythology, Set - God of Chaos, usurper of his brother Osiris' throne, Arch Enemy of his nephew Horus and all-around bad guy - was nevertheless the one charged with protecting Ra's sun-barge from the serpent Apophis.
 * Some argue that this is The Artifact of Set previously being a positive chaotic figure embodying destruction and renewal like that of a desert storm.
 * One Indian folktale was about a king whose palace was constantly infested by mice. The king then orders his servants to send in cats to get rid of the mice, but then the king gets fed up with the cats, and first tries to get rid of the cats with dogs, then tigers, and finally an elephant. When the king becomes annoyed with the elephant, the servants get rid of it with yes, a mouse.
 * Made into a Looney Tunes short

Newpaper Comics

 * In FoxTrot, Paige is writing a fairy tale where she is a self-insert. Her character comes across a trapped troll that suspiciously looks like Jason, and is faced with the choice of freeing it or hoping a boar would come along and eat it. The last panel is Paige asking if they make "boar whistles" that work, presumably, like dog whistles.

Tabletop Games

 * Pretty much what the whole Summoner type of wizard is about in Dungeons and Dragons; note that as such wizards become more powerful, the category "monster" may include summoning intelligent creatures from other planes of existence, such as dragons, angels, demons and genie. A necromancer on the other hand may summon various types of undead to deal with whatever troubles him. The druid can summon giant animals, elemental spirits and dinosaurs to do his bidding.
 * As most creatures a summoner can summon are only about half as strong as the caster at best, this is more of a case of summoning a swarm of smaller fish.
 * Until he learns Gate (one of the most powerful spells in the core game), which allows the summoning of monsters considerably stronger than the ones the players would expect to fight.
 * An interesting case is summoning a Bebilith. It's a demon who is best summarized as "a demon who hunts and kills smaller demoms". There is even one specific spell which summons an uncontrolled Bebilith that will attack whatever is next to him, but will go for other demons first at all times.
 * Thankfully a summoned creature can not summon more creature. However, there is a slightly different form of summoning called "calling", and called creatures can call more creatures as powerful as themselves with the notorious gate spell. A rules exploit commonly called "chain gating".
 * In First Edition AD&D Pit Fiends were powerful lower-plane monsters (Devils) who among their many abilities included the use of the Gate spell at will, including being able to summon other Pit Fiends with it, with no specific limitations.
 * A similar version of this could happen in older versions of Warhammer Fantasy Battle and Warhammer 40000, as the old Realms of Chaos books (Slaves to Darkness and Lost and the Damned) included rules for releasing daemons bound into weapons. The daemon released would be a bog-standard example of the type, with the standard equipment. It was possible to get a daemon weapon containing a Bloodthirster of Khorne, whose standard equipment at the time included... an axe containing a Bloodthirster of Khorne. In terms of balanced points battles, it was a game-breaker, with the number of Greater Daemons you fielded (in addition to your army) limited only by the number of turns you were playing, and the number of Bloodthirster models you owned...
 * This currently possible again in the Storm of Magic expansion with scrolls of binding that allow you call in any monster from the earlier rulebooks, including greater daemons, as well some monsters created for the expansion. These monsters are "biggest fish" available, including stronger version of the greater daemons, a supersized giant, a giant mammoth, and super versions of the dragons, some of which can be made lord level wizards. This is more balanced than old means of bringing out bound daemons since the controlling player has to pay for the monsters in point cost like they do everything else.
 * A variation of this trope occurs in the Warhammer40000 background: with Hive Fleet Leviathan rapidly closing in, the higher-ups of the Imperium decided to divert the swarm into an Ork-held star system as a last-ditch delaying effort. As of the current fluff, they're still going at it, but Imperial generals (rightly) fear that whoever wins will have become much stronger, and will be coming after them next...
 * Call of Cthulhu (tabletop game) supplement Terror From The Stars. The Field Manual of the Theron Marks Society says that when facing extremely powerful monsters, "The only hope in this situation is to summon another deity or monster with a natural hatred for whatever it is that is attacking."
 * The Jurassic Park card game allowed you to summon a Tyrannosaur to scare off the smaller predators, the venom-spitting Dilophosaurs and pack-hunting Velociraptors. Or even another Tyrannosaur. But then you would have to fight off the T-Rex as well, after it scared the others off.
 * Changeling: The Lost features a Goblin Contract known as "Call the Hunt." Unless you're a Loyalist (or truly, truly desperate), use of this Contract is considered a very bad idea.
 * To further elaborate: most Goblin Contracts have some kind of drawback to go with their main effect. In the case of Call the Hunt, the main effect is that drawback.
 * Mutants and Masterminds has a summoning power. A drawback you can take for it makes everything you summon hostile toward you. You might summon a bigger fish to deal with your foes, only to have to summon another when the first turns on you.
 * In the storyline of the Deadlands CCG Doomtown, the Big Bad was eventually defeated by
 * Exalted Sorcerers can do this as well, albeit in a slow and complicated fashion, by summoning and binding demons. Terrestrial Sorcerers can at most bind First Circle Demons, which are easily on par with most Terrestrial-level fighters one-on-one. Celestial Sorcerers can summon and bind Second Circle demons, the pinnacle of which is represented by Octavian, the Living Tower, who rules a quarter of Hell and is not a Third Circle only by a technicality. Third Circle Demons are, well... One of them is Ligier, the Green Sun (literally). His sword is an army in and of itself, with its own stats; if you can defeat it, he calls you a worthy foe and offers you a chance to walk away. Anyone foolish enough to actually fight him can explicitly only win by Storyteller fiat.

Video Games

 * Scribblenauts will allow you to put God vs Cthulhu.
 * You can also summon an Arapaima if you literally just want a bigger fish.
 * Also Cthulhu vs. Satan.  wins.
 * Additionally "God vs. Vampire".  wins.
 * This trope constitutes much of the gameplay in the final level of Eternal Darkness.
 * Then in the Real Ending we learn that essentially
 * Grim Grimoire has this as well in the infamous battle.
 * Doom II has a special level just for this purpose. In it, you are presented with both a Cyberdemon and a Spider Mastermind, the two most powerful monsters in the entire game, at the same time. The only way you will survive this is if you provoke one into firing on the other, then take out the survivor.
 * That's just the easy way to kill them. For the same reason you are able to singlehandedly defeat either of them, however, you are also perfectly capable of defeating both. You just need more ammo.
 * There's also an earlier non-secret level in Doom II which features a room with at least twenty Barons of Hell and a single Cyberdemon. Due to the way they are positioned, the Cyberdemon will immediately shoot at you as soon as you open the door, but since the Hell Knights are standing in the way, they'll get hit and turn on the Cyberdemon. It's very likely the Cyberdemon will win this fight, but by the time he does, he's so weakened that it won't take much to kill him.
 * In the original Doom, there was a secret level with this premise. In the room you start with there are half a dozen Barons of Hell. In the next room are a dozen Cacodemons. The best survival strategy involves running from room to room, allowing the monsters to mix and get caught in each other's crossfire, which will make them turn on each other as long as you aren't fool enough to draw their attention.
 * In the Grand Finale of (the main questline of) The Elder Scrolls IV: Oblivion, Martin Septim summons.
 * The Elder Scrolls V: Skyrim gives you scrolls that can summon animals to your aid, spells that can summon atronachs (embodiments of the elements) or a Dremora Lord to fight for you, and a shout that can when far along in the main quest.
 * Early in Iji the plan with dealing with the Tasen is to alert their much more powerful enemies about their presence..
 * In Dragon Quest VI, about halfway through the game a kingdom summons a legendary demon in the hopes that it will kill their world's Crystal Dragon Satan for them. Normally, what happens is the demon is too powerful to control and ends up destroying the kingdom for their arrogance. However, if you have an insanely overpowered party (we're talking months of grinding or the use of a gameshark here), you can beat the demon in combat and gain its respect, resulting in a funny bonus ending in which the demon flies over to the final boss and curbstomps him for you.
 * Said demon, Nokturnus, can be created for your party in one Dragon Quest Monsters to invoke this trope once again. DQM: Battle Road Victory lets you sic various Final Boss monsters and more for similar results.
 * Whenever Super Robot Wars include Neon Genesis Evangelion, a strategy that can be useful against powerful enemies is to let EVA01 be destroyed. Instead of getting removed from the tactical map, it will go berserk, gain massive stat boosts, and will destroy most enemies with ease. However, it's uncontrollable and might attack your units instead (and you still need to pay its 40000 repair cost.)
 * In Super Robot Wars Alpha however, the use of a special item called Tem Ray's Circut can cheeze this, setting the Repair cost to a measly 10 Credits... while taking a hit on other stats.
 * The Metroid species have this as their entire purpose. When the X Parasites were discovered to be insanely destructive and dangerous, the Chozo genetically engineered the perfect predator to get rid of them. Decades later, when Samus kills all the Metroid species, the X parasites' population explodes.
 * Bayonetta slays all bosses (and many of the larger, normal mooks) by summoning greater and greater demons.  Always a bigger fish, indeed. And she does it with her hair.
 * Also in the battle against  she summons several demons of growing strength in a sort of summoning style Worf Effect.
 * BioShock 2 has  as a plasmid.
 * Fossil Fighters: When an ancient elemental dinosaur of power is called up, you not only Summon Bigger Olympus Mons, you summon the one with an Elemental Rock-Paper-Scissors advantage!
 * Mass Effect 3: At one point, all the heavy artillery is destroyed before a Reaper can get blasted with it, and the heroes appear out of options for dealing with said Reaper.
 * The titular rifts of, well, Rift can sometimes be triggered by specific actions. Since all six of the elemental planes hate each other, this can be a quick way to get out of a hairy situation.
 * In Dead Space 2, Isaac has to get past a government security force with orders to shoot him on sight. How does he do it? By powering down the lights and door locks, leading to a massive army of necromorphs slaughtering their way through the government forces.
 * In Guild Wars Prophecies,
 * In Baldur's Gate 2: Shadows of Amn, a powerful wizard can summon various massive demons like Cacofiends and Pit Fiends to face whatever the enemy is. But unless you cast Protection from Evil on your party, it will then go after you.
 * In Freedom Force vs The Third Reich you summon your greatest enemy, the Time Master, an insane supervillain with complete control over time and space to fight Entropy, an insane supervillain who grows more powerful as things become more chaotic while she's in the process of ripping the universe apart.
 * The Immortal. So, you end up in a flooded dungeon. You row left, you get sucked and drowned by a whirlpool. You row right, you get chased and drowned by tentacled monster. Solution? Lure tentacled monster into a whirlpool. You get better, though.
 * The 'Summon Baatezu' ability given to Hellfire Warlocks in Neverwinter Nights 2 works like this. A powerful Devil will fight by your side for a number of rounds, but if you keep it around too long, it might turn on you...
 * Played with in In Famous, the reason the ray sphere was made was because
 * That's not even the end of it. In inFamous 2, it's revealed that
 * Subverted, and then paired with Nice Job Breaking It Villain, in Tales of Phantasia. Dhaos needs but the only way he can get it is from the World Tree; which humans are bleeding dry through their use of Magitek. So he sends (what he thinks) is an even stronger army of monsters out to smash their weaponry, resulting in the biggest conflict in the world's history. However, not only do his efforts completely fail (because the humans have the Five-Man Band on their side), but it's implied that the war he kickstarted led to the version of the present where Mana is all but gone; making it impossible for him to fulfil his goal anyway.
 * Done twice in the Golden Sun series.
 * An antagonistic, but not evil, example occurs for the final battle of The Lost Age, wherein the heroes are the "Big Fish". So, what Bigger Fish does summon to stop them? Why,  The heroes win, obviously, but the intention was still there.
 * Part of Golden Sun: Dark Dawn revolves around you hunting down and activating the biggest BFG in Weyard's history so it can be used to destroy
 * In the ending of the normal path in Soul Nomad and The World Eaters, the heroes face the finalboss, three Physical Gods merged into a single monster.
 * In Monster Hunter Tri, A relatively low-level monster known as the Qurupeco has the ability to mimic the calls of other monsters and summon them to it's aid. In higher-level hunts, this usually involves monsters much nastier than it is.
 * In Monster Hunter Tri, A relatively low-level monster known as the Qurupeco has the ability to mimic the calls of other monsters and summon them to it's aid. In higher-level hunts, this usually involves monsters much nastier than it is.

Webcomics

 * Darths and Droids is the Trope Namer.
 * In Eight Bit Theater, Garland has the innate power to summon any kind of monster. Problem is, he's not very smart.
 * Nukees Gav, when in the after life and faced with a giant snake, decides to summon the god of alcohol, who has sworn to kill Gav.
 * After Bun-Bun first shows up in Sluggy Freelance Torg and Riff try to get rid of him by hiring a grizzly bear to be the new Team Pet, on the condition that he gets rid of Bun-Bun first. Turns out grizzly bear < mini lop.
 * Lightning Made Of Owls has Summon Bigger Cthulhu. As if one wasn't enough.
 * When Mike of College Roomies from Hell gets attacked by a large octopus, he realizes the small knife he has won't be enough to win the battle so he cuts himself, attracting a shark with the smell of his blood to attack the octopus for him.
 * This happens in It's Walky! when SEMME is attacked by the Britjas (British ninjas; don't ask). After getting fought to a stalemate, they use the Power Booster Rod (a tree branch containing absurd amounts of extradimensional energy; again, don't ask) to summon The Wanderer, a being with god-like power who is very interested in keeping dimensional travelers out of his dimension. The Britjas are travelers from another dimension. Guess what happens.
 * Done as Parody in Nodwick, the heroes are going to make a barbeque for the locals so they go out hunting, first thing they catch is a rabbit, then they use that one and everything they caught to go up to foodchain until they catch a tarrasque, one of the biggest and most fearsome (and also most foul smelling) animals in the world.
 * Done in Grim Tales from Down Below. Twice. The first time wasn't so effective and the second time got copied and lost the effectiveness of his best attack. Then the monster got serious
 * Dominic Deegan pulls this off here
 * Done to some interesting effect an early Apple Valley. In an attempt to counter a giant rampaging Apple of Chaos (evil cousin to The Apple of Discord), Doctor Hubris uses a magic wish to summon Gayzilla from a sister comic by the same author. A careful read-through of the archives shows that Gayzilla did *not* exist as part of the Apple Valley continuity beforehand, but has ever since.
 * What do you say to an angry god to keep from getting killed? If you're a character in User Friendly, the answer is "Hastur Hastur Hastur."

Web Originals

 * In Kickassia, the resistance invoke this trope onto, convincing him to  to combat the Nostalgia Critic.
 * Note that Linkara thought it was a stupid plan and asked if Angry Joe was high when he planned it.

Western Animation
"Charlie Brown: Meet the kite-eating tree, you ugly son of a bitch!"
 * In the "Super Best Friends" episode of South Park David Blaine has brought the giant stone statue of Abraham Lincoln to life and it is terrorizing Washington D.C. The SBFs solution: build a giant stone statue of John Wilkes Booth, which sneaks up behind the Lincoln statue and shoots it in the back of the head.
 * In the first segement of Futurama: "Anthology of Interest I", a 500-foot Bender is attacking New New York City. According to Prof. Farnstworth, the only thing that could stop him would be "an even more equally big monster", and so he uses his growth ray on Zoidberg to battle him.
 * In the Grand Finale of Jackie Chan Adventures, Shendu is freed to combat his son Drago, who had absorbed the powers of all of Shendu's siblings. While they are battling, Uncle sends them both into another dimension.
 * There were a few occasions where The Real Ghostbusters had to let the Stay Puft Marshmallow Man out of the containment unit to fight another huge ghost hand-to-hand while they figured out how to put it down for good.
 * The Venture Brothers' Brock Samson engineered a situation like this when he and the Ventures were simultaneously hounded by the OSI and the Monarch, pitting the two against each other as a double use of the trope.
 * Jerry from Tom and Jerry sometimes sought protection from Tom in Spike the bulldog. Odd, since in Real Life dogs also kill mice and rats, sometimes just for fun.
 * One of the great moments in Robot Chicken: The Peanuts gang have almost all been killed off by The Great Pumpkin, and Charlie Brown, fleeing for his life, cowers at the base of the tree. The Great Pumpkin notices all the half-eaten kites and has time for an Oh Crap before this Crowning Moment of Awesome:

"*Lizards ate all the pidgeons* Skinner: Well, I was wrong. The lizards are a godsend. Lisa: But isn't that a bit short-sighted? What happens when we're overrun by lizards? Skinner: No problem. We simply unleash wave after wave of Chinese needle snakes. They'll wipe out the lizards. Lisa: But aren't the snakes even worse? Skinner: Yes, but we're prepared for that. We've lined up a fabulous type of gorilla that thrives on snake meat. Lisa: But then we're stuck with gorillas! Skinner: No, that's the beautiful part. When wintertime rolls around, the gorillas simply freeze to death."
 * In The Real Adventures of Jonny Quest, the Quests enlist the aid of an Animal Wrongs Group they had a run in a few episodes earlier, to stop Surd who happens to be brainwashing whales.
 * In the episode "The Shrieking Madness" of Scooby Doo Mystery Incorporated, Scooby and the gang face Char Gar Gothakon, The Terror that Hath No Name, a creation of H.P. Hatecraft. In the course of defeating the Cthulhu stand-in, they get assistance from Harlan Ellison. Seriously. (This was easily the weirdest Scooby doo episode ever.)
 * From an episode of Ben 10 Ultimate Alien. After getting it handed to her pretty well by her crazy, full anodite cousin Sunny, Gwen admits she can't beat her. And promptly calls her other full anodite relative, her Grandma Verdona, who easily puts Sunny in her place.
 * Done in the original series too, during Secret of the Omnitrix. When Vilgax and his giant robots are set to annihilate Ben and his friends, Azmuth unlocks Way Big, Ben's strongest alien form, a giant who throws Vilgax into space like a softball.
 * The Simpsons did this 4 times in a row.

Real Life

 * Has happened a few times with invasive species. An example is in Australia, where rabbits had become a serious problem, so foxes were imported to try and kill the rabbits. As often with this trope, the foxes became a problem in themselves, while having little effect on the Rabbits.
 * While we're on the subject of rabbits, it's theorized that the reason they scream bloody murder when seized by a predator is because it just might invoke this trope, causing a rival predator to intervene and giving the rabbit a slim chance to get away.
 * Also, dinoflagellates light up when they are being eaten, in order to literally summon a bigger fish (that presumably does not eat dinoflagellates) to consume their current attacker.
 * Can often happen in geopolitical situations as well. See, for example, the U.S. supporting mujaheddin in Afghanistan.
 * A reason a great many people in many nations supported Nazi Germany was because they wanted to build it up to oppose the U.S.S.R.
 * The best example that comes to mind if Finland. The Soviets were looking over the border and licking their lips, and soon enough invaded. The fins put up a good fight, and then signed up with the Nazis who the USSR was just not ready to deal with quite yet. A bigger fish indeed.
 * It also applies later in World War Two when the Nazis showed their true colors and the US and Britain backed Stalin against Hitler.
 * The Aztec and Incan empires were so brutal to the peoples they ruled that many of the lesser Indian nations were more than willing to join the conquistadores in conquering those empires.
 * Related: in the American West, many Indian tribes would use an alliance with the white man to gain leverage over their enemies.
 * A very popular video shows some lions attacking a wildebeest calf near a watering hole. The struggles of the calf in the water attract a crocodile, which tries to fight the lions for their prey and gives the calf a chance to escape. However, the crocodile loses and the lions are about to set upon the calf. Then the entire wildebeest herd masses on them...
 * When Kuwait was invaded by Iraq and completely overwhelmed, it resorted to asking the United States to push Iraq out knowing America had interests in it. This mostly worked as intended, with America and its coalition allies beating Iraq easily despite initial fears, though Iraq getting desperate during the coalition air campaign pummeling for weeks sadly resulted in them dumping a large amount of Kuwait's oil into the sea and setting its oil wells on fire in a desperate attempt to force the coalition to attack.