->'''Billy Jack:''' I'm gonna take this right foot, and I'm gonna whop you on that side of your face... and you wanna know something? There's not a damn thing you're gonna be able to do about it.\\
'''Mr. Posner:''' (''sarcastically'') Really.\\
'''Billy Jack:''' (''nodding'') Really. (''does exactly what he promised'')
-->-- ''Billy Jack''

We all know just how awesome the {{Badass}} is, whether they look the part [[MuggingTheMonster or]] [[CrouchingMoronHiddenBadass not]]. Unfortunately, not everyone else in the film or TV show does, even when the former is the case.

So maybe our hero walks into a bar, where some of the regulars don't take too kindly to him. Or maybe a couple of thugs accost him on the street. Sure, he might look dangerous, but he's outnumbered and outgunned, so he shouldn't be a problem, right?

The viewers watch with bated breath for the moment that these guys [[OhCrap find out that they've woefully underestimated the level of badassery involved.]]

Compare BewareTheNiceOnes, GoodIsNotSoft, TheSoCalledCoward, MuggingTheMonster, YouWouldntShootMe, DudeWheresMyRespect. Contrast with BullyingADragon, where the perpetrator antagonizes someone [[TooDumbToLive despite knowing full and well how Badass they are and without any perceived advantage.]]



[[folder:Anime & Manga]]
* In ''Manga/FullmetalAlchemist'', Edward Elric is often underestimated due to his height. [[TheNapoleon Bad]] [[BerserkButton idea]].
* ''Anime/TengenToppaGurrenLagann'': Because Simon is a skinny young kid, no one (except Kamina) ever respects him as much as they respected his muscular older bro, even though Simon is and always has been infinitely more powerful than Kamina.
* Happened all over the place in ''OnePiece''. The [[BigBad villains]] and minor [[JerkAss assholes]] often underestimated [[TheHero Straw Hat Luffy]] or [[TheLancer Zoro]] when they first meet, but sometimes the Straw Hats themselves fall prey to this.
** Somewhat justified since this series is filled with [[{{Cloudcuckoolander}} Cloudcuckoolanders]] and [[CrouchingMoronHiddenBadass Crouching Moron Hidden Badasses]].
** Which makes at least one major aversion rather notable. When Luffy learns that his brother is on death row, he resolves to rescue him, despite knowing that said brother is in the pirate crew of [[WorldsStrongestMan Whitebeard]], who is absolutely ''[[PapaWolf guaranteed]]'' to make a move to rescue him already, and is far better equipped to do so. Everyone tells Luffy that he'll be in completely over his head if he tries to butt in, and they're ''absolutely right''. Luffy spends the entire battle getting repeatedly [[CurbstompBattle curbstomped]] by pretty much every antagonistic named character he encounters, needing to get bailed out by either a member of Whitebeard's crew, or one of the allies he made in [[TheAlcatraz Impel Down]]. In his defense, though, he does manage to pull a few crucial moves, and is the one who eventually rescues Ace. [[spoiler: Briefly.]]
** Donquixote Doflamingo is a stand-out aversion, as he has actually observed other people underestimating Luffy and his crew many times in the past and suffer humiliating losses. His approach against them is to finish them off as quickly as possible.
*** That said, once he gets the upper hand, he starts falling prey to this. Law even pointed this out by asking him if he's going to be one of the countless many that would come to regret underestimating the Straw Hat Pirates.
** Sugar lampshades this to the dwarves
* In ''Anime/DarkerThanBlack: Ryuusei no Gemini'', Section 3 underestimates Hei after they {{Depower}} him, and Genma thinks that he's "just a [[TheStoic gloomy]] [[ChickMagnet gigolo]]." But remember that this guy was called "Black Reaper" ''before'' he [[EmpoweredBadassNormal became a Contractor]]. Somewhat justified in that prior to Hei's HesBack moment solidified in this episode, Genma had pummeled him fairly easily in an earlier fight, although the ability of Hei to survive a beating from a psycho with InstantArmor power is itself impressive.
** It's not the only time, either. Witness the woefully-overconfident assassin teams sent to kill him during the {{interquel}}s; you'd think [[NamesToRunAwayFromReallyFast that nickname]] would be a bit of a tip-off, but this is apparently not the case.
* In ''Manga/MahouSenseiNegima'', upon arriving in a Magic world bar Negi is attacked by a random thug because he resembles a guy who beat him sorry many years ago - actually Negi's infamous father "[[WorldsStrongestMan The Thousand Master]]". In retrospect that should got him thinking...
** For the record, that "random thug" is Vargas, one of the baddest guys in town, and pretty [[OvershadowedByAwesome everyone who's not Negi (or Kotaro, or Chachamaru, who were with him)]] would do well not to underestimate ''him''. More importantly, Vargas, his little brother Tohsaka, and their mother become plot-relevant [[MauveShirt Mauve Shirts]] later.
** Interestingly enough, [[spoiler: Nodoka]] pulls this on the one of Fate's associates.
-->"You made the mistake of thinking of me as a mere powerless girl, Mr. Mage."
** Anyone who ever thought that fighting [[MemeticBadass Jack]] "[[RedBaron Thousand Blades]]" [[CrazyAwesome Rakan]] is a good idea. Like Fate's minions believing they could take him on a 4 on 1 fight. He's the personification of awesome for a reason, people.
* ''LightNovel/{{Durarara}}'''s Shizuo Heiwajima, Ikebukuro's resident [[RedBaron God of Destruction]], doesn't particularly look like the sort of person who would ([[MusclesAreMeaningless or even could]]) uproot vending machines and beat people half to death with them when he's not actively doing so. Thus, many people don't realize that it's a bad idea to pick a fight with the skinny guy in a bartender suit until it's far too late.
* Many groups in ''IchibanUshiroNoDaimaou'' seem to have Akuto in the sights of their manipulations, and casually talk about pushing him aside or disposing of him or some such, which would be incredibly stupid considering his "Demon Lord" status. And this isn't even getting into those dumb thugs that tried to pick a fight with him and instead ended up with broken limbs.
* The title character of ''{{SWOT}}'', Manabizaki, is a bespectacled nerd who studies too much. He has a HairTriggerTemper and a tendency to mouth off to people. Naturally, every delinquent in school was practically lining up to beat the crap out of him and put him in his place. After all, he's just an overly-studious nerd, ain't he? [[BadassBookworm They're]] [[HardHead always]] [[MadeOfIron weaklings,]] [[FoeTossingCharge right?]]
* North Italy/Feliciano in ''Webcomic/AxisPowersHetalia.'' This could arguably apply as well to Austria and Finland, given their histories.
* The Thompson sisters in ''Manga/SoulEater'' make this mistake regarding the skinny boy in the suit who comes looking for them. It's also noted in canon by Maka that Kid looks so 'low-key' and unimpressive that it's easy to forget he's a death god and so a ''very'' formidable opponent when he feels like it. His [[SuperOCD eccentric behavior]] only enhances that impression. A similar claim could be made about his father Shinigami, although all who have encountered ''him'' so far know what they're dealing with and are appropriately wary.
** Not to mention Blair. Disregarding the fact that the series began with the protagonists ''overestimating'' her badassery, in the Clown arc she takes up about a third of the action fighting the Flying Dutchman, who thinks she's just an annoying cat. She kills him by stealing his hat and tricking him into committing suicide to get it back.
* A serial occurrence in ''Manga/{{Naruto}}'' (indeed, in a lot of shonen) due to a combination of this trope and JustAKid. [[OnceAnEpisode The amount of times a villain has smack-talked]] one of [[BunnyEarsLawyer the heroes]]...
** Characters underestimating Naruto more often comes because they simply knew him as a struggling ninja academy student, post time skip, it became less common, especially since he started win enough fights that would more liken make other afraid to take him on.
** Kabuto is a repeat offender, even when, by all rights, experience should have taught him better. Then again, he is SmugSuper and a colossal {{Jerkass}}. [[spoiler:Surprisingly averted by ''Madara'' (the real one), of all people. He actually respects Naruto's abilities, and this is a guy who considers everyone but the First Hokage an unworthy challenge.]]
* War Relief Section III in ''Anime/PumpkinScissors'' has a reputation as a "[[MildlyMilitary cheery little unit]]" which was only put together by the government as a public relations gesture. By far most of the antagonists of the series assume they're a bunch of incompetent, ineffectual idealists, only to discover that the "cheery little unit" is bringing all of their plans crashing down upon their heads. Especially applies to GentleGiant [[TheBigGuy Randel]], a SuperSoldier who successfully fights tanks ''on foot''.
* Anime/{{Monster}}: Several characters made the mistake of underestimating a certain blonde haired gentleman by the name of Johan Liebert.
* Misaka Mikoto from ''LightNovel/ACertainMagicalIndex'' is the third strongest esper in Academy City, and everyone knows about her, yet for some reason delinquents frequently try to hit on her, generally resulting in them getting electrocuted. In fact, in the first scene of the first episode of the anime the main character is running from delinquents that he got to chase him because they approached her carelessly. In the end, she still zapped them. Making it even worse is that she's always wearing the uniform of a highly prestigious school that is well-known to only accept espers of Level 3 or higher, and is the only facility in the city to boast ''two'' Level 5's among its students, so anyone wearing that uniform is likely not someone to be trifled with.
** There are only seven Level 5 espers in Academy City. Each is explicitly a OneManArmy and the stronger ones like Accelerator, Dark Matter, Railgun and Meltdowner are an outright PersonOfMassDestruction. FridgeLogic would dictate that punks would get their photographs and avoid any of them at all costs but no, if you thought trying to punch out [[ShockAndAwe Mikoto]] was bad, there are idiots who try to attack [[AxCrazy Accelerator]]!
** It only gets worse from there too. Later in the series, {{God}} (yes that one) is [[SerialEscalation somewhere around the]] ''fifth'' strongest entity in the series, and the ones stronger than he/she/it are underestimated a fair amount. Like that one time [[PersonOfMassDestruction Accelerator]] ([[OvershadowedByAwesome not on that exclusive stronger than God list]]) tried to attack [[PhysicalGod Aiwass]] (the strongest entity in the series). Aiwass' ''passive defenses'' would have killed him in his SuperMode. To put a comparison on their powers, Accelerator is to Aiwass as your average Level 1 is to Accelerator.
* ''Manga/RurouniKenshin'' has two varieties of people underestimating Kenshin. One, they know about his reputation that earned him the nickname [[RedBaron Hitokiri Battousai]] (roughly translates as [[NamestoRunAwayFromReallyFast 'God-like drawn sword' the manslayer]]) and try to fight him anyways, or they take his refusal to kill as a weakness. Either way, the results for them prove very painful.
* A lot of people in {{Berserk}} tend to underestimate Guts. Many of them just don't buy that somebody can actually swing that [[{{BFS}} ridiculously large sword]] of his or [[OneManArmy kill as many men as he has singlehandedly]], while the Apostles refuse to acknowledge that a mere human can kill or even defeat them, [[TooDumbToLive despite knowing very well that he fought countless other Apostles, killed them and lived to kill others]].
* This tends to happen to Nanashi in ''Anime/SwordOfTheStranger'', since most of his enemies don't expect some random guy, armed only with a sword that he can't unsheath, to be able to kill several simultaneously attacking samurai. Which he does. Multiple times.
* Firo Prochainezo from ''LightNovel/{{Baccano}}'' is one of the Martillo family's top fighters, second only to Ronnie ([[spoiler:who's more or less an ''EldritchAbomination'']]). He also a small, baby-faced pretty boy that looks so harmless that ''children'' think they can take him on without much trouble. Czeslaw finds this amusing.
* A lot of vampires sent to defeat Alucard in the earlier chapters of ''Manga/{{Hellsing}}'' (mainly Luke Valentine and Allambra) have the bad habit, while perfectly aware of his reputation, of thinking of him as a simple very powerful vampire and believing they can take care of him easily. This usually lead them to a gruesome and horrible death when finding out Alucard is actually a HumanoidAbomination at his weakest, and will turn into an EldritchAbomination if he happens to take the fight seriously.
** Similarly, Zorin, despite being warned by the Major that Integra and Seras Victoria weren't to be underestimated, disobeys orders and attacks the Hellsing mansion, assuming it was helpless without Alucard around. She ends up killing and insulting Seras' LoveInterest, leading her to evolve into an actual vampire and granting Zorin a death that would have made Alucard proud.
* The Supreme Kai in ''DragonBallZ'' both underestimates and overestimates badassery. He overestimates his enemies, even in cases where it's quite illogical, and is repeatedly surprised by how freakishly strong the Z fighters are. Had he come to Earth with a rational assessment of their power, rather than a poor assumption, things would have gone a lot better.
* In ''Manga/SangatsuNoLion'', this is one character's fatal mistake during a shogi tournament semi-final match that results in that character's loss. He initially writes him off as just another opponent (reducing him down to just his rank) in his fervor to go up against another character in the finals, not realizing the accomplishments under his semi-final opponent's belt would indicate the true strength in his abilities.
* In ''Manga/MagicalGirlLyricalNanohaVivid'', new character Einhard vocally questions whether such warm, caring people like Nanoha and Fate could be good at magical combat. [[FunnyBackgroundEvent Nove almost falls over keeping herself from laughing at this.]]
* An interesting case of this pops up during ''{{Manga/Bleach}}'' With the good guys(The Vizards, and various Soul Reapers) focused so hard on avoiding Aizen's ''Zanpaktou'', which allows him to completely hypnotize anyone who sees its ''Shikai'' form, they forget one vital thing: Aizen is the strongest Soul Reaper next to Yamamato, and proceeds to demonstrate he doesn't need his sword's powers to utterly crush them in battle.
* In ''Manga/BlackLagoon'', at the beginning of the first "Killer {{Meido}}" arc, some local yahoos make the mistake of thinking that [[ImplacableMan Roberta]] is an easy target because she's a milk-drinking ''Meido.'' ''Bad'' mistake.
** Later on, at the beginning of ''El Baile De La Muerte,'' some of them make the ''same'' stupid mistake about [[spoiler: Roberta's protege Fabiola.]] [[WhatAnIdiot You'd think they'd learn...]]
** Anytime an outsider comes to Roanapur, they're either the biggest badasses around or complete morons. A perfect example would be when a Florida mafia enforcer tries to boss around the [[GunForHire mercenaries]] he hired to capture Jane. [[KnifeNut Shenua]] calmly explains to him that they're not a bunch of "gangbangers who get off on graffiti-ing walls"; every one of them is a professional killer.
** And in the Japan arc, [[JerkAss Chaka]] thinks that [[BewareTheNiceOnes Rock]] is perfectly safe to abuse and mistreat, even though he's part of the [[TheMafiya Hotel Moscow]] delegation and his [[DarkActionGirl girlfriend]] is right there.
* Averted in ''Anime/SenkiZesshouSymphogear G'', when Tsubasa tells Maria not to underestimate her. Maria responses that she won't underestimate her and fights her with full power.
* In ''Manga/MotherKeeper'' Zelik is a man in his 50s, he's short and disabled, but underestimating him will be the biggest mistake of your life. Proven by the time Syal made this mistake and narrowly avoided him punching a hole through her.
* Nearly everyone in ''Webcomic/OnePunchMan'' underestimates Saitama, either because of his goofy costume or his poor hero rank. Needless to say, he's the single most powerful character in the series.
* When the Noah's Ark Circus launches an attack on Phantomhive Manor in ''Manga/BlackButler'', they completely write off [[spoiler:the household staff]]. Turns out [[spoiler:Ciel didn't hire his staff for their household abilities - he has Sebastian, after all - but as ''security'']]. None of the circus crew survive the attack.
* In the early volumes of ''BattleAngelAlita'' A.K.A ''Gunnm'', Alita/Gally was underestimated by many of her enemies and paid the price, starting with the arrogant bounty hunter named Zapan. In the sequel Manga, ''Last Order'', her reputation as one of the strongest warriors in the universe proceeds her.
* In {{Manga/Bleach}}, you have Yhwach. While he is currently the main villain, every confrontation he has been in so far involves the Shinigami underestimating him(or fighting a [[spoiler:copy]] and confident in their abilities to defeat him. They often seemingly do appear to have the advantage over Yhwach, before Yhwach reveals himself or a new aspect of his power that turns the table. It has been Yhwach's advantage throughout the arc - the good guys know so little about his power that he consistently blind-sides his enemies.

* This happens a few times in ''ComicBook/{{Watchmen}}'', especially a number of times with Rorschach: attacked by bullies when he was a kid, when he and Nite Owl hunt for info in a bar, when he's attacked in prison...
* This is why Apollo and Midnighter lose to CaptainAtom in ''Captain Atom: Armageddon''. The pair think Atom is just another super-powered mook, not realizing that Atom is more powerful than all the members of ComicBook/TheAuthority combined, including Jenny Quantum. The only reason they last as long as they did is that Cap refuses to go all out against people he barely knows, even ones who are currently trying very hard to kill him.
** Really, just about every superhero in the Wildstorm universe was guilty of this. Midnighter and Apollo were just the most egregious case because they were the last. They knew, or should have known, that Cap had already beaten Mr. Majestic, the WildCats, and the Engineer, all of whom were also guilty of ''severely'' underestimating Cap, to the point where the WildCats deliberately attacked one at a time, as if it were a game.
* Countless Super Villains: Franchise/{{Batman}}'s just a [[BadassNormal guy in a costume.]]
** And a few super heroes think SelfDemonstrating/TheJoker's [[WhatAnIdiot just a]] [[MonsterClown clown with too much free time.]]
** Psh, {{Robin}}'s just some TagAlongKid {{Sidekick}}. And {{Nightwing}}'s just a pretty boy in spandex.
* Speaking of {{Nightwing}}...Oh, look at that the "Kid Sidekicks" think they're going to form a [[{{ComicBook/TeenTitans}} hero team of their own]]. Ha! Go back to school kiddies. Oh...you just knocked a world-destroying demon into next week ''and'' fought the JLA to a standstill in your first outing?
* In the fourth and final issue of the ''{{JLA-Avengers}}'' crossover, the supervillain Prometheus, who can pretty much download any fighting capabilities he wants, confronts CaptainAmerica and says, "I've just uploaded Batman's fighting skills. [[TemptingFate That'll be more than enough to defeat you]]." Cap replies, "[[PreAsskickingOneLiner Oh]]?" On the next page, Cap is seen hitting Prometheus hard enough to break his helmet.
* Happens to {{Spider-Man}} quite frequently. He's a lithe guy who swings around a lot, wears silly pajamas, and makes stupid jokes. New villains tend to forget that he's held his own with the Avengers, the X-Men, and fought just about every villain in the Marvel Universe. (The rule of thumb is, when he stops cracking wise, start running and you don't stop till you're out of New York state.)
* Has happened a few times to [[IronMan Tony Stark]], whether because his identity was still secret and therefore it's assumed that he's just a rich playboy who needs a bodyguard to protect him, or because it's assumed that he's helpless without his armor. The thing is, it's generally a bad idea to attack someone who's been taking lessons from CaptainAmerica for about a decade unless you're a professional, considering Tony once [[CrowningMomentOfAwesome beat the crap out of a bunch of Skrulls]] who were pretending to be Comicbook/TheAvengers, and he did so with his ''bare hands'' while ''naked'' and while his heart was ''slowly giving out''. And then there is, of course, this immortal exchange:
-->'''Tony:''' [''to his kidnapper''] I was just wondering, [[PreAsskickingOneLiner does your guard here know what a clavicle is]]?
-->'''Guard:''' Huh?
-->'''Tony:''' [''karate chop''] Surprise! [[CrowningMomentOfFunny It's what I just broke]]!
* ComicBook/{{X 23}} gets sexually harassed pretty regularly. Yes ''[[{{Wolverine}} that]]'' [[OppositeSexClone X-23]]. Of course, she appears to be a normal and quite attractive teenage girl but still...
* In Volume 2 of ''TheInvisibles'', [[http://img.photobucket.com/albums/v337/skandha/king-mob-squeezes.jpg a stereotypical redneck learns the hard way]] not to insult a sexy transvestite and then go pick a fight with her bald associate...
-->'''King Mob''': [''after taking the unlucky local'' ''[[GroinAttack firmly in hand]]''] I'm telling you you're in the wrong '''film''', Fatboy. You're not in the '''cowboy''' film [[WrongGenreSavvy you thought you were in]]. This is a '''[[FunctionalGenreSavvy different]]''' kind of movie. And you're in the scene where the redneck shitkicker picks on the '''stranger''' in town, only it's '''[[Film/TheTerminator Big Arnie]]''' or a gang of '''[[Film/FromDuskTillDawn vampires]]'''. I'll bet you've seen that a million times, Cowboy.
* In ''The Hard Goodbye'' arc of ''Comicbook/SinCity'', the bouncer for Katie's Bar throws out a customer, looks at Marv and tells him to leave. Marv calmly grabs his face, breaks his nose and goes in. The rest of the staff apologizes for the bouncer.
** That entire story is set up by the fact that the all-powerful Roarks thought it would be a piece of cake to frame a murder on a big, ugly drunk, unaware that he was extremely dangerous.
* Most people of Alysia in the first books of ComicBook/LesLegendaires mainly remember the Legendaries as a bunch of failed heroes who caused the infamous Jovenia Incident that turned everyone into a child when trying to save the world. As such, in the first books, their name wasn't even impressive to anyone, to the point two thugs are shown laughing when they introduce themselves. What those people tend to forget is that the Legendaries also foiled several times the plans of a [[TheDreaded much feared]] SorcerousOverlord with a massive body count, and actually succeeded in defeating said SorcerousOverlord. They fortunately get their respect back after the Anathos Cycle.
** One especially hilarious example is during the fight between Razzia and Dark-Razzia, when Razzia announce he is going to kick his ass in memory of his sister:
--->'''Dark-Razzia''': [[EvilLaugh Ah Ah Ah]] ! [[SmugSnake You]], kick my ass ? [[TemptingFate I would like to see tha]]... ([[KilledMidSentence Razzia punches him through the face]] with [[LivingWeapon Amy]], sending him flying meters away)
--->'''Razzia''': I warned him, didn't I?
--->'''Amy''': I confirm!
* Happens surprisingly often in ''ComicBook/{{Diabolik}}'' with the titular protagonist, Ginko, Eva Kant and Altea. While understandable with Eva (who doesn't look that dangerous, even if she's a KillerRabbit) and Altea (a socialite and not that good a fighter, but damn smart and determinated), it's pure BullyingTheDragon with Diabolik, AKA the [[NamesToRunAwayFromReallyFast King of Terror]], and Ginko (the one cop who can actually hold Diabolik in check, and who has personally punched him out in more than one occasion).

[[folder: Fan Works]]
* ''Manga/{{Evangelion 303}}'': [[FieryRedhead Asuka]] thought that she could deal with a rookie any day of the week. It turned out that rookie –[[TheHero Shinji]]- was just as good as her and won their friendly [[OldSchoolDogFight duel]].
* In the ''{{Series/Firefly}}'' fanfic ''Fanfic/{{Forward}}'', this happens multiple times. The badguys repeatedly underestimate the crew in general and River and Jayne in particular, assuming the former is just a small teenage girl and the latter is just dumb muscle. In the "Last Man" story, the [[BadassCrew Six Rifles]] especially underestimate just how resourceful a young Jayne Cobb is when they take a contract to kill the robbery crew he was on.
** In the ''Wrath'' arc, the Academy agents who defeated, captured, and interrogated River eventually conclude that she is a psychological wreck who underestimated ''their'' capabilities simply because she's a very dangerous psychic assassin. [[spoiler: Then River reveals that ''she planned the whole thing'' and then cuts the power to the building while still tied to a chair.]]
* The four, who mostly look normal and wimpy, take advantage of being underestimated whenever possible in ''Fanfic/WithStringsAttached''. In fact, they win the day because the skahs (and Jeft, for that matter) cannot conceive of them being competent, especially after George and Ringo are [[BroughtDownToNormal depowered]].
* In ''[[FanFic/ThingsWeDontTellHumans Things We Don't Tell Humans]]'', Jolt does this to Bumblebee. In the flashbacks, most of [[OldMaster Terratron's]] other students do this to Prowl when they first meet, and Megatron does this to Optimus Prime when they have their first "argument" as rulers. Starscream severely underestimates Faust, too.
* ''[[FanFic/UltimateSleepwalker Ultimate Sleepwalker: The New Dreams]]'' features PsychoForHire Bullseye, who brags about being an A-list supervillain and mocks the supposedly C-list 8-Ball when they end up fighting during a MobWar. [[spoiler:The ensuing fight ends with 8-Ball using his jet-propelled cue stick to flick Bullseye's detached head into a garbage can.]]
* After Luso in FanFic/TheTaintedGrimoire failed the mission he gave him, several months later, Baron Popple doesn't think he could win against [[spoiler: Suzuka]]. He was wrong.
* ''[[FanFic/FriendshipIsMagicTheAdventuresOfSpike Friendship Is Magic: The Adventures Of Spike]]'': According to Spitfire, ponies tend to do this about the Wonderbolts, often forgetting that despite being most well known for stunt shows, they ''are'' part of the military. And they show it during the changeling invasion.
* In the ''Franchise/HarryPotter'' [[AlternateUniverseFic AU]] ''FanFic/{{Empire}}'' the Sorting Hat puts Harry in Hufflepuff so that he can have the advantage of everyone underestimating him.
* In ''FanFic/TheJadedEyesSeries'' aspiring EvilOverlord Tristan Winter (a.k.a. Harry Potter) [[WeCanRuleTogether tells Voldemort that he may permit him to rule along side him.]]. At first Voldemort thought he was joking. Then Tristan proceeds to demonstrate just how very powerful and well-connected he and his minions are.
* A common theme with the newly human Biju in ''[[http://ficwad.com/story/213011 Eroninja]]'' is to underestimate everyone else. This includes Nel/Sanbi who was turned into a child, Urd who was born from a fragment of the Hachibi, and human opponents as well. They quickly learn that despite their appearance and origin respectively, Nel and Urd ''are'' Biju and that some humans can hold their own against a Biju, even if they can't win.
* The [[Literature/HarryPotter Veela]] leader in ''[[https://www.fanfiction.net/s/8933408/17 Wizard Runemaster]]'' tells [[Videogame/WorldOfWarcraft Onyxia]] people are "far more than [the] mere parlor trick" that is their Allure. In response, Harry tells Onyxia to "undo her parlor trick", transforming back into a massive dragon.
* In ''Anime/{{Pokemon}}'' fanfic ''FanFic/{{Symbiosis}}'' Poison Lance, a weedle, tells off the [[HellHound houndhoom]] chasing after Ash and Mareep that if they turn away he will spare their lives. The houndhooms laugh in his face, [[AllWebbedUp big]] [[RetiredBadass mistake]].
* In the ''[[Fanfic/AradsStardust Stardust]] sequel ''Mente Materia'', recovered documents reveal that [[spoiler:Vide]] doesn't consider the changelings, griffons or minotaurs a threat to their operations, to the point of not even including details on their capabilities or recommended countermeasures.

[[folder:Films -- Animation]]
* Po Ping of the ''WesternAnimation/KungFuPanda'' franchise tends to get this a lot due to being, well...[[CaptainObvious a panda]]. The underestimating isn't limited to the bad guys either, as even his own allies tend to be surprised by what he can actually pull off.
** Tai Lung in particular REALLY underestimates Po.
-->'''Tai Lung''': ''(to Shifu)'' Him? [[CaptainObvious He's a panda.]] ''(to Po)'' [[DepartmentOfRedundancyDepartment You're a panda.]] [[ArrogantKungFuGuy What are you going do do, big guy? Sit on me?]]
-->'''Po:''' Don't tempt me.
** About a minute later, Po actually '''does''' sit on him, on the stairs.
** The sequel has Lord Shen do this as well, despite him literally being ''destined'' to lose to him. Although Shen does kill a far more well-known kung fu master at the beginning of the film, so he can at least be forgiven.
* In ''WesternAnimation/TheBookOfLife'', Manolo gets this treatment from [[BigBad Xibalba]], [[spoiler:when the God arrogantly believes that Manolo can't warn La Muerte about his cheating or pass his final test. He's proven wrong both times]].
* ''WesternAnimation/ThePrinceOfEgypt'' shows Rameses and his priests initially viewing the Hebrew God with careless contempt. Then the Plagues start.

[[folder:Films -- Live Action]]
* ''Film/BillyJack'':
-->'''Billy Jack:''' [[BadassBoast I'm gonna take this right foot, and I'm gonna whop you on that side of your face... and you wanna know something? There's not a damn thing you're gonna be able to do about it]].\\
'''Mr. Posner:''' ''(sarcastically)'' [[TemptingFate Really.]]\\
'''Billy Jack''': ''(nodding)'' Really. ''(does exactly what he promised)''
-->-- ''Billy Jack''
* ''Franchise/StarWars'':
** The cantina scene in ''Film/ANewHope''. A couple of criminals don't take too kindly to Luke Skywalker, and probably don't think the old guy with him would be much help in a fight. A few seconds later someone's lost an arm.
*** Shortly afterwards, Greedo the Rodian bounty hunter thinks he has smuggler Han Solo helplessly cornered. Unfortunately for him, Han prepares his blaster under the table, which he fries him with.
** Jabba the Hutt came to power during the Republic's heyday. He survived the Clone Wars. He was positively ''thriving'' with the Empire. The Rebellion and Luke Skywalker probably seemed small potatoes compared to them. He was wrong.
** Yoda was severly underestimated by both Count Dooku in ''Film/AttackOfTheClones'' and by Palpatine in ''Film/RevengeOfTheSith''. While the latter managed to take win, it wasn't an easy one.
* In ''Film/TheRundown'', The Rock plays a "retrieval expert", and in the opening scene a client has sent him to collect a debt from a professional football player. Having approached the player in a club, he gets a drink thrown in his face before looking round to see that half the team has surrounded him. Sighing, he explains that they can do this the easy way or the hard way -- they choose the hard way. Cue one guy beating up seven or eight huge athletes with ease.
* In ''Film/ShaolinSoccer'', Mighty Steel Leg is beaten up in a bar because he's not allowed to fight back. The same thugs meet him on the street and throw insults. One of them throws a football at him, he kicks it back HARD.
* ''Film/Terminator2JudgmentDay''. The T-800 walks into a bar in the buff, tells some punk to give him his clothes and his motorcycle. The punk starts a fight. Guess what happens?
** The biker punks of the original {{Terminator}} learned the hard way that they were TooDumbToLive when he wanted clothes. They're lucky that the Terminator in question just let them live.
*** Well, mostly.
* The ''{{Zatoichi}}'' series in Japan lives on the basis that people are always underestimating Zatoichi because he is blind, but is really an extremely deadly swordsman.
* The kidnappers in ''Film/BigJake'' assume, just like [[PhraseCatcher everybody else in the movie]], that [[JohnWayne Jacob [=McCandles=]]] ([[BadassGrandpa grandfather]] of the boy they kidnap) is ''dead''. Naturally, it never occurs to them that he might be [[{{Determinator}} the one coming after them]]. Had they known, it is very likely that they would have chosen to kidnap ''somebody else's'' grandson.
** The head kidnapper (Richard Boone) ''can'' tell that the man following them is a {{Badass}}, and [[LampshadeHanging says as much]]; what he doesn't know is just ''how much'' of a badass he is, or how ''[[ThickerThanWater personally invested]]'' he is in the outcome of the situation.
* ''Film/UnderSiege'': Casey Ryback? Yeah, he's [[StevenSeagal just a cook]]
* ''Film/SecondhandLions'': When Hub is harassed by a group of ne'er-do-well greasers in a tavern, he not only kicks their asses (FOUR to ONE) but takes them home with him and teaches them what it means to be a man. Bad. Ass.
* In ''IpMan 2'', the friends of Wong Leung who he calls to challenge Ip think he looks like a laundryman, while one of the Hong Kong masters thinks his name sounds lame. They have no idea.
* The opening scene of ''Film/TheMatrix'' has this with the cops ignoring the Agents' orders and trying to apprehend Trinity themselves.
--> "No, Lieutenant, your men are already dead."
* This happens to Frank Martin a ''lot'' in ''Film/TheTransporter'' movies. No one seems to expect a chauffeur to be a {{Badass}}. Frank and Lai do it to TheDragon in the first film, whom they believe to be a sleazy AmoralAttorney, and not the BloodKnight he really is.
* Captain America in ''Film/CaptainAmericaTheFirstAvenger'', shortly after becoming a super soldier, thanks in part to [[spoiler:Dr. Erskine's death]], he was pretty much placed onto a USO entertainment group seeing how they don't really have much of a use for the supersoldier program. When entertaining American troops in Italy, the soldiers were not impressed with his performance (one of the soldiers was also implied to have mooned him, and they eventually pelt tomatoes at him while demanding for the girls to return). Of course, after he singlehandedly rescued 400 soldiers in one of Schmidt's bases, they began to realize he really is that badass.
* Happens surprisingly often within ''Series/{{Airwolf}}''. Of course, most people don't count on a helicopter being more well-armored than a tank, being capable of flying at speeds up to Mach 2.5, flying into the stratosphere, and carrying enough firepower to wipe a small country off the face of the earth.
** According to Tang Von Soong (referring to String, who is perhaps the world's best combat pilot), "Fortunately such people have little stomach for the nature of war".
** Also happened with Robert Winchester, who was able to give String a run for his money in the Airwolf Simulator. The Firm restricted his role from potential Airwolf pilot to scientist because he didn't quite have the same "natural talent" for flying that String had.
* When the title character of ''Film/{{Hancock}}'' is serving time in prison, he is accosted by some thugs he'd gotten thrown in there. They attempt to threaten him, [[TooDumbToLive apparently forgetting]] that Hancock is a superhero on par with {{Superman}}, but with none of his sense of fair play or justice.
-->'''Hancock:''' [[BadassBoast If you don't move, your head is going up his ass. Y'all fellas sure you wanna ride this train?]]
-->'''Matrix:''' [[TemptingFate Choo choo, asshole...]]
--> (what follows is extremely painful... not to mention humiliating, as Hancock [[NotHyperbole wasn't exaggerating when he made that threat]]. [[AssShove OU]][[{{Squick}} CH!]])
* {{Tap}} (1988): "But since you ain't got no legs..."
-->'''Mo:''' You know what this young man said? We ain't got no legs! Dat means, I ain't got no legs, you ain't got no legs, and dem men in there ain't got no legs! Now what's dat sound like to you?
-->'''Sandman:''' ''A challenge!''
** And the rest of the gang comes storming in to show Max a thing or two.
* In ''Film/KnockaroundGuys'' local big shot Brucker seriously underestimates [[VinDiesel Taylor]], and gets this [[CrowningMomentOfAwesome little speech]] and a [[CurbStompBattle serious beat down]] for his trouble:
--> '''Taylor:''' 500.
--> '''Brucker:''' 500 what, douche bag?
--> '''Taylor:''' 500 fights, that's the number I figured when I was a kid. 500 street fights and you could consider yourself a legitimate tough guy. You need them for experience. To develop leather skin. So I got started. Of course along the way you stop thinking about being tough and all that. It stops being the point. You get past the silliness of it all. But then, after, you realize that's what you are.
* In ''Film/TheAvengers'', Loki starts ranting at the Hulk as a mindless brute and his inferior. While this is an incredibly stupid act on anyone's part, Loki is quite arrogant, egotistical, and most importantly, a god. The idea that the Hulk could take him probably never entered into his mind. The Hulk proceeds to beat the "puny god" down like a [[MetronomicManMashing freaking rag doll.]]
* Almost a running gag in Christopher Nolan's ''Film/TheDarkKnightSaga'', even among people who theoretically know what they're dealing with:
** ''Film/TheDarkKnight'': When the Joker appears, Batman, somewhat hypocritically, dismisses him as just one man who couldn't possibly be more dangerous than the mob. He ends up destroying quite a bit of the city, [[EvilerThanThou driving the last nail into the mob's coffin]] [[NearVillainVictory and almost doing the same for Batman]], and [[TheCorrupter drives Harvey Dent to madness.]]
** ''Film/TheDarkKnightRises'': Batman, who has been out of action for roughly eight years, gets back in the batsuit, and is able to hunt down and capture several League of Shadow members who were trying to escape a bank robbery. The primary villain Bane manages to get away. Batman dismisses Bane as just another one of Ra's al Ghul's flunkies. When Bruce and Alfred review tapes of Bane's assault on the bank, Bruce brushes away Alfred's assessment of Bane's combat abilities, stating that he'll simply "fight harder". He teams up with Catwoman to go underground and take out Bane, only to be outsmarted by Bane and lured into a trap. It's only thanks to the ensuing CurbStompBattle that Batman realizes just how dangerous Bane really is.
* In ''Film/StarTrekIntoDarkness'', when being questioned by Kirk, John Harrison makes a snide comment about Spock being a Vulcan and how Spock wouldn't know savagery like him. [[spoiler: Spock proves him wrong when he delivers a brutal beatdown on Harrison/Khan after Kirk's death]]. There is a good reason why Vulcans suppress their emotions.
* Elle in ''Film/LegallyBlonde'' is constantly underestimated and looked down on, simply because most people see her as a DumbBlond. She proves them all wrong when she got into Harvard with a 179 (one mark away from the perfect test) score on the LSAT and again, when she used her knowledge of haircare, to win her first case. And she was only a first year law student!
* In ''Film/{{Godzilla 2014}}'', Admiral Stenz has some doubts about Godzilla's ability to defeat the Mutos, in spite of chasing one of the Muto out of Honolulu and hardly being affected by the Navy's gunnery in San Francisco Bay.
* Considering the reputation that [[Franchise/TheChroniclesOfRiddick Riddick]] has, being more or less the most wanted single person in the galaxy and arguably the most dangerous, it's ''amazing'' how many people seem eager to pick a fight with him. Bounty hunters, lawmen, criminals, Necromongers. Even when they have superior numbers, they're never enough. Even when all he has is a tea-cup, that just means he gets [[CoolAndUnusualPunishment creative]] with how he [[CruelAndUnusualDeath kills]]. Eventually, the survivors learn, until the next batch shows up.
* ''Film/RomeoIsBleeding'': When Jack first meets Mona, he's expecting to be impressed due to her fearsome reputation, but he "doesn't see it." She deadpans, "Keep lookin'."
* ''Film/KingsmanTheSecretService'':
** [[spoiler:Arthur himself get this treatment when he underestimates Eggsy, who had switched out his poisoned drink]].
** Eggsy is underestimated by his stepdad and accompanying thugs, none of whom realise that Eggsy is fresh from Kingsman training and [[spoiler: ''saving the world'']].
%% ** Some thugs with a beef with Eggsy make this mistake after calling Harry Hart a grandpa. He had had a very emotional day and needed to let off a little steam.

* In ''Literature/ABrothersPrice'', the kidnappers who kidnap Jerin are clever enough to search him for hidden weapons, and even find his set of lockpicks. However, they still underestimate him, as he [[spoiler: pretends to stumble against them, and steals his stuff back just a moment after they took it.]]
* This happens a couple of times in ''TheQueensThief'' series. In ''The King of Attolia,'' Eugenides [[spoiler: spends the whole book practicing only basic sword routines in the public practice courts, and then reveals himself to be the best swordsman any of the soldiers have ever seen by trouncing an entire squad.]] People always forget that he had two grandfathers.
** This often happens to Eugenides, most notably when he manages to single-handedly destroy [[spoiler:the house of Erondites, which was powerful enough to pose significant threat to the the Queen's reign, and, in the same scene, scares the crap out of his attendants and thus gains their loyalty.]]
-->'''Attolia:'''[[spoiler: Ninety-eight days. You said it would take six months.]]
-->'''Euginides:'''[[spoiler: I like to give myself a margin when I can.]]
** He even lampshades it: [[spoiler:"Has it occurred to you, Costis, that the only reason I'm alive is that those three assassins took me for a prancing lightweight?"]]
* It's not a real fight, but in ''[[XWingSeries Wraith Squadron]]'', the Wraiths ask Wes who the greatest pilot alive is, and Wes considers for a bit, then says it's their commanding officer, Wedge Antilles, because of his killcount and time in active service. Falynn Sandskimmer scoffs at this, says that he might have been good in the past but got old and became washed up. Wedge tolerates this for a bit, then challenges her to a race in ore haulers and wins handily after toying with her a bit.
** How does he win? Amongst other things, he drops his ore hauler on top of hers, pushes off hers, and plops down right at the finish line. The only thing she can say? "You cheated." His response is yes, of course, because combat isn't a game. And if she wants to live through the war, she had best learn to cheat ''better''. Of course, teaching Wraith Squadron to cheat might have been an example of GoneHorriblyRight.
** Also not a direct fight, but in several of Wedge's appearances in the ''NewJediOrder'' and later ''Literature/LegacyOfTheForce'', people underestimate his abilities in all kinds of things. Not piloting, but things like the ability to tell when he's being used as a political pawn about to be sacrificed, and in general his extraordinary resourcefulness and endless skill with the IndyPloy and, sometimes, XanatosSpeedChess.
* Elsewhere in the ''Franchise/StarWarsExpandedUniverse'', the heroes spend the latter half of ''Literature/GalaxyOfFear'' on the run from the Empire, which finally puts up a bounty on them for any [[BountyHunter random hunters]] to see. While the first one the heroes encounter is an amateur, he's aware of Hoole's [[ShapeShifter capabilities]] and prepared to counter them, taking Zak hostage at blasterpoint and planning to [[WhyDontYouJustShootHim just shoot Hoole]] and bring the kids in alive. However, he's clearly not aware that Tash has been [[MindOverMatter developing her skills with the Force]].
* ''Literature/CodexAlera'': Anyone who is in a fight with [[BadassNormal Tavi]]. Period. That [[TheCallPutMeOnHold "furyless freak"]] ''will'' hand you your ass if you get him angry.
* ''Literature/HarryPotterAndTheDeathlyHallows'': [[spoiler:Molly Weasley's "NOT MY DAUGHTER, YOU BITCH!" followed by her killing [[TheDragon Bellatrix Lestrange]], who laughs at her and has only a second to be shocked when she realizes what's just happened.]]
** Most people don't take the three main characters too seriously, either, until they start winning. Meanwhile, Neville, Luna and Ginny ran a successful resistance against Voldemort's followers' rule of Hogwarts for the better part of the school year [[spoiler: although it was made easier by Snape being a good guy]].
** Especially in the earlier books, where Harry, Ron, and Hermione are usually dismissed by older wizards because of their [[JustAKid young age]]. Even in some of the later books, information is intentionally kept from them because other characters are worried it'll be too much for them to handle (which is [[SubvertedTrope sometimes true]]).
** It seems that everyone (including himself) thought that Peter Pettigrew was a weakling. He was able to accomplish many feats of difficult magic, and was eventually responsible for the death of two of his old friends.
* In Creator/LarryNiven's ''Literature/KnownSpace'' setting, the [[ProudWarriorRaceGuy Kzin]] first encountered humanity in the form of an unarmed colony ship from a pacifist world, carrying only a skeleton crew. Seeing easy prey, they attacked. Unfortunately, "unarmed" and "pacifist" don't add up to "harmless" [[spoiler: and a communications laser is still a laser...]]
** This is a frequent trope in this universe. The [[PlanetOfHats alien race that prides themselves on being cowards]] can deliver quite a kick with the leg that is towards you when they turn their back on you...
* ''Literature/{{Discworld}}'': "Sure, she's wearing the uniform of the City Watch, but she's just some pretty blond. How tough can she really be? Let's take her hostage again!" Protip, criminals: Captain Angua von Uberwald is also a ''werewolf,'' and one of the toughest and most dangerous members of the City Watch.
--> '''Carrot'''(As Angua is taken into a bar): Try not to hurt anyone.
--> '''Thug''': As long as you do what we say, she'll be fine.
--> '''Carrot''': Sorry, was I talking to you?
** Also from the Watch, almost every antagonist will eventually underestimate Vimes and/or Carrot's ability to foil any EvilScheme, regardless of the odds involved.
** Cohen the Barbarian often gets this. He is a very, very old barbarian hero, but people tend to forget that in this line of work, one doesn't live that long unless they are very, very good at it.
** Lu Tze of Literature/{{Discworld}} fame does his bit to spread rule number one: "Do not act incautiously when confronting little bald wrinkly smiling men." Most of the population is more than willing to go along with this rule. When he meets those few who don't, he has to educate them in why the rule is in place.
** This seems to happen to Granny Weatherwax in about half the books she's in. The other witches get it too, but it's generally Granny who puts them down.
* ''Literature/TheWheelOfTime'': Gawyn and Galad, both of whom are highly-trained swordsmen, together take on a just-recovering [[CrouchingMoronHiddenBadass Mat Cauthon]] who is armed with only a quarterstaff. [[CrowningMomentofAwesome Mat]] [[CurbStompBattle wins]].
* In Literature/TheDresdenFiles there are a good dozen or more of persons or entities who look weak, pathetic, foolish, dim, and easy prey. They are not to be laughed at. They are not to be looked down upon. They can and will kick your ass, if they don't just kill you. Here is just a small sample of the most frequently occurring examples.
** So there's this guy. He's a tall but gangly fellow, looks [[PermaStubble perpetually unshaven]], [[BadassLongcoat wears a big coat]] and walks around with a [[SimpleStaff big stick]] and generally seems like a scruffy, weird sort, but is otherwise not really all that much of a threat. A great many people, both {{Muggle}} and supernatural, consider him to just be some freaky guy with eclectic fashion sense. Except this guy's name is Harry Blackstone Copperfield Dresden, titular character of ''TheDresdenFiles''. Conjure by it at your own risk. After all, this is the man who has taken on all kinds of supernatural beings and survived every encounter. [[spoiler:He killed a Faerie Queen, stared down and nearly killed [[PersonOfMassDestruction Nicodemus Archleone]]- ''twice'', reanimated a ''dinosaur'' and marched it through the streets of Chicago, and genocided the entire Red Court of vampires [[PapaWolf because they took his daughter]]]]. The supernatural types eventually start [[TheDreaded coming to realize how dangerous he is]], but the {{muggles}}? Not so much.
** So, there's this short woman, 5 foot tall, and like the example below, about 100 pounds. Head of the Special Investigations department for at least 8 years, while most last 2 weeks. Shot a half-ton werewolf monster from point-blank range. Once killed a plant monster with a chainsaw, and hamstrung an ogre with the same. [[spoiler:One-hit-killed a PhysicalGod with a holy sword, after having cut through countless EliteMooks, any one of whom could tear an ordinary human to pieces. She drove away a FallenAngel by drawing the same sword about 2 inches out of its sheath. Later, she killed a Faerie Queen that was about to kill the man she loves.]] And that is only the beginning of how extremely BadAss she is.
** Ebenezer [=McCoy=]: An old Scottish redneck living on a farm in the Ozarks. Sounds relatively harmless? He's one of the most powerful wizards in the White Council, and fuck with him or his loved ones and he will [[spoiler:[[ColonyDrop pull a satellite out of orbit and drop it on your head like squashing a bug]]. If that is not a viable option, he will simply kill you with a wave of his staff. With one wave, he killed about 100 {{Muggle}} mercenaries.]]
** Thomas Raith. Drunken {{bishonen}} playboy who [[ObfuscatingStupidity doesn't seem to care about much but enjoying himself]]. Until you hurt someone he cares about. Then he can and will rip your arm off and beat you to death with it before you have time to blink. A surprising number of people don't quite realize what it means that even though Lord Raith [[OffingTheOffspring habitually kills his sons]], Thomas is still alive.
** Ivy, the Archive: A tiny slip of a girl who is the [[HumanHardDrive repository of all human knowledge]], and can blast a fallen angel into oblivion with an OffhandBackhand. Remember, knowledge is power. She has a LOT of knowledge. Ergo, she has a LOT of power. Q.E.D.
** So, there is this small fairy named Toot-toot. He is about 12 inches tall. He cannot understand complex orders as he has a very LiteralMinded. And he is a pizza addict. [[spoiler:But he is incredibly quick, able to change directions on a dime, and with his trusty box cutter, he will take on a {{Skinwalker}}. Slicing into the ancient evil. Even one of the most powerful wizards in the world was impressed by how well he handled himself against a PhysicalGod-tier force.]]
** So, there's this guy dressed in what seems to be a pretty authentic recreation of a full set of Centurion armor. He has a cigar and is just generally wandering around being [[SmugSnake smug and arrogant.]] Then he uses ''half'' of [[spoiler: Harry's]] Name to bring [[spoiler: him]] to [[spoiler: his]] knees with no particular effort when [[spoiler: Harry]] starts giving him lip. This guy just so happens to be Ferrovax, the single oldest Dragon alive and is by [[WordOfGod Word of Jim]] a being that could go toe-to-toe with [[PhysicalGod Mab, the Queen of Air and Darkness.]]
** Donar Vadderung is not the head of the organization that hires out people like [[{{Valkyries}} Gard]] as hired guns for no reason. When Harry seems to be taking his power lightly (specifically, the power of a dozen beings he describes as being not quite as strong as he is), he gives a little demonstration via [[spoiler: slamming Harry into the ground with his raw will, leaving Harry as helpless as an "insect watching the shoe coming down".]] Even weakened, the guy is still a PersonOfMassDestruction. This makes sense, considering that Mr. Vadderung is [[spoiler: actually, literally, a PhysicalGod. Odin to be precise. And if you're to young to comprehend how scary that is, he's also Santa Claus. Be afraid.]]
* Chloe from ''Literature/DarkestPowers''. She is five feet tall and weighs a hundred pounds, ''maybe''. She's in decent shape, but considering her size and her lack of any real self-defense training, she's not that much of a physical threat. [[NightmareFuel She can raise an army of zombies in under five minutes just by thinking about it too hard]].
* Vin from the ''{{Mistborn}}'' series is another one of those five-nothing, hundred-pound girls who's constantly overlooked and underestimated because of how unimposing she looks. She killed a PhysicalGod, ''vertically bisected'' a man ''and his horse'', headbutted someone in the face hard enough to reduce his head to PinkMist, and has abused her SuperStrength so much that she's essentially dependent on it to function, but also gets about three times more power out of it than anyone else. Most amusing when she's facing [[OurOrcsAreDifferent Koloss]]; they tend to get very confused while [[OneManArmy she slaughters them by the hundreds]] because they don't get how it's even possible for someone so little to beat someone much bigger.
** Elend gets it too, for a different reason. He was well-known among the nobility as a [[WideEyedIdealist head-in-the-clouds-idealistic]] scholar with little practical experience with the outside world. Not all of them have gotten the memo that [[TookALevelInBadass things are a bit different now]].
* SienkiewiczTrilogy has a glorious example at the beginning of the second book. The protagonist, Andrzej Kmicic, mocks his opponent, Michał Wołodyjowski, before their duel. What happens next is such [[CurbStompBattle a one sided fight]] that Kmicic ends up begging his opponent to just kill him already and spare him more humiliation.
* As you might expect in a military SF series, ''Literature/HonorHarrington'' contains a goodly number of examples:
** Right off the bat, the enemies of the titular heroine regularly find, to their regret, that she's not as easy a target as they first thought:
*** In the backstory a fellow midshipman at the academy tried to rape her in the shower, not realizing she was a {{heavyworlder}} in Earthlike gravity. She beat the shit out of him, but unfortunately wasn't brave enough to press charges.
*** In ''Field of Dishonor'', a professional duelist hired to kill Honor dismisses her as a serious threat on the dueling field, though he grants that she is a capable starship captain.
*** In the next book, ''Flag in Exile'', she gutted and decapitated a trained swordsmen in one movement after having only spent a few months learning the sword, in part because her opponent was in the mindset of winning swordsmanship tournaments, not killing opponents.
*** One of the major villains in ''Honor Among Enemies'' dismisses Honor as a threat when taking her as a hostage... right before she cold-bloodedly guns down some pirates with an antique weapon, and reveals that she has arranged for the pirate shuttle that was trying to escape to be rigged with a bomb, destroying them before they could get away.
*** After that point, everyone in the universe suddenly became GenreSavvy and [[TheDreaded now want absolutely nothing to do with Honor Harrington if it might involve a face-to-face fight]].
** A less conventional example comes in the form of [[spoiler:Manticoran Admiral Augustus Khumalo]]: his own navy considered him to be a [[ByTheBookCop by-the-book]] political appointee lacking both imagination and tactical and strategic experience, but when [[spoiler:Terekhov discovered Mesa's plan to conquer the Talbott Quadrant]], he demonstrated a tough-mindedness and adaptability that none of his fellow officers anticipated by backing his subordinate to the hilt, even at risk of [[spoiler:war with the Solarian League]].
** On the level of fleets, rather than individuals, the outcomes of not a few battles are radically affected by one side learning that the other's hardware is a lot better than anticipated -- starting in the very first book, when the Manticoran light cruiser ''Fearless'' goes toe-to-toe with [[spoiler:a massive Havenite Q-ship]]. The LensmanArmsRace that follows results in a lot more such surprises from both sides, especially when [[spoiler:the Solarian League -- whose peacetime navy was, as of the first book, roughly on par with Manticore -- discovers what happens when you join the arms race late]].
** The aforementioned Terekhov rather succinctly described the trope when the local dictatorship of a backwater planet threatened to start mass executions of civilians if he didn't leave which they are confident he will do because the Manticorans make a point of being the good guys. [[spoiler: In his last message to them before a kinetic weapon strike from orbit utterly obliterates their headquarters and leadership]], he asks:
-->"Why is it that people like you always think that you're more ruthless than people like me?"
* ''RangersApprentice'': Halt is rather short, wears a mottled cloak, rides a shaggy pony, and has unevenly cut, greying hair. Underestimate him at your own risk.
* In the backstory of ''Literature/EmpireOfTheAnts'', the whole ant population of France severely underestimated the Dwarf Ants, believing them to merely be small, weaker ants. In the following days, they took over Black Ants, Red Ants, Wasps, Termites... When the protagonists Red Wood Ants finally confront them, they discovered to their horror the Dwarf Ants had several queens in each of their colony, making them dangerous ZergRush specialists, and possessed high intelligence for the specie. By the time the story has started, the two species has become nemesis to each other.
* In the Literature/SherlockHolmes short story "The Speckled Band", Dr. Roylett, having learned that his step-daughter paid Holmes a visit concerning the suspicious nature of her sister's death and the strange atmosphere now surrounding her, attempts to intimidate Holmes by bending an iron poker with his bare hands. After Roylett's departure, Holmes, now even more interested in the case than he already was, informs Dr. Watson that had Roylett stayed, he would have seen that Holmes possessed an even level of strength by bending the poker back to it's proper form.
* In the Robert Browning telling of "Literature/ThePiedPiperOfHamelin", the Mayor and Corporation (his advisors) decide to renege on their promise to pay the Piper the agreed-upon fee for ridding the town of rats. Their thinking is that since the rats were drowned and "What's dead can't come back to life", there's nothing the Piper (a wanderer whom they regard as beneath them) can do in retaliation for the promise being broken. He warns them that he can use his music as an instrument (so to speak) of revenge, but they don't take the threat seriously and effectively dare him to try it. They learn to their eternal sorrow that his music also works on humans -- specifically, ''children''.
* In Literature/TheTomeOfBill, Sally is frequently subject to this. Marlene and Jeff[=/=]Night Razor knew her before she became a vampire and was just a normal human. They learn the hard way that Sally's probably the biggest badass in the series.
* Happens from time to time in ''ASongOfIceAndFire''.
** Taking time out of your life expectancy to gloat at, belittle or threaten [[LittleMissBadass Arya]] [[ActionGirl Stark]] gives her more time to make you feel very, very sorry you bothered, for instance.
** Or, how about laughing in the white-haired old man's face or just dismissing him as "old"? If that's [[KnightInShiningArmour Ser]] [[BadassGrandpa Barristan]] [[OneManArmy Selmy]], you've just proved what a jackass you are.
** And, heaven help you if you insult [[ManipulativeBastard Tyrion's]] intelligence by assuming he can't talk himself out of the bind you've just put him in: the odds are good that he can.
** Finding yourself facing a plain woman in *snicker* armour? Go ahead, attack like a demon in a frenzy because 1) you don't want to be beaten by a girl and/or 2) you want to look impressive when you beat her for mates points. Unfortunately... it's probably going to result in 3) you being wiped along the floor. That's Brienne of Tarth, and she's a {{Badass}} StoneWall who just [[CombatPragmatist suckered you]] into a loss.
** But, to win a Crowning Moment of Underestimation... you have to beat Kraznys mo Nakloz, a Good Master of Astrapor for his underestimation of Daenerys Targaryen. Repeatedly insulting somebody you should very well know for a fact is descended from an exiled branch of Valyarian Dragon Lords in the Valaryian language over several days is... [[{{Jerkass}} a bit crass]], but kind of understandable. They were the historical masters of your city and you hate them, so getting your digs into one of their few remaining descendants makes sense. Convincing yourself, however, that this mere slip of a girl without much visible backup won't be able to understand you or the nature of the very dragon you hope to gain in trade is... [[WhatAnIdiot dumb]]. Handing her the army of invincible, obedient slaves in the middle of your (now) poorly defended city ''before'' full receipt (and control or containment) of the mobile [[BullyingADragon flame-thrower you then precede to yank the chain of]] (literally)? And, um... you were calling her stupidly new to this whole negotiation thing, [[TooDumbToLive Mr Charcoal Briquette]]?
* Tris from ''Literature/{{Divergent}}'' is a small teenage girl. Far too often, she's assumed to be a non-threat - even when she's pointing a gun at them.

[[folder:Live Action TV]]
* ''Series/{{Angel}}'' played with this trope in the first episode. Cordelia suddenly realised her potential sponsor was actually a vampire and Angel appears on the scene. When her fake sponsor doesn't seem at all bothered by Angel's appearance, Cordelia realises that it's because he not only doesn't know Angel's a vampire, but doesn't know just how dangerous a vampire Angel is. Unfortunately, her gloat of "You don't know who he is, do you? Oh, boy, you're about to get your ass kicked!" backfires. Not only did the vampire not know who Angel was, but Angel and Cordelia didn't know who he was. Turns out, the ones doing the underestimating were actually Angel and Cordelia. By the end of the episode, this situation has been very much reversed. Permanently, one might say.
** And in the season 5 finale of ''Series/{{Buffy|the Vampire Slayer}}'', right after a PreviouslyOn summing up the entire series to date:
-->'''VAMPIRE:''' *moving towards Buffy* I don't mind a little appetizer...
-->'''BUFFY:''' You ever heard the expression, "biting off more than you can chew"? Okay... um, how about the expression, "Vampire Slayer"?
-->'''VAMPIRE:''' [[TooDumbToLive What the hell are you talking about]]?
-->'''BUFFY:''' Wow! Never heard that one? Okay, how about, "Oh God, my leg, my leg?" *breaks his leg*
-->'''VAMPIRE:''' Oh God, my leg! Ah!
** The basic premise of the franchise is to make the 90-pound cheerleader that the monster corners in an alley capable of ripping its arm off.
** A non-monster instance occurs when Buffy squares off against Tara's father in "Family". Mr. Maclay has no idea that Buffy could kill him with her bare hands and, given what a mysogynistic AbusiveParent he is, it's a real shame we don't get to see her show him.
* Multiple times on ''Series/BurnNotice'', especially in "Rough Seas", when Michael poses as a nervous nerd with an inhaler... only to turn on the group of drug dealers he's infiltrated when they least expect it. Also notable is "Bad Breaks", in which a bank robber has the bad luck to rob a bank with both Michael and Agent Jason Bly inside.
** He's had it done on him once or twice; [[spoiler:Lucy Lawless as an assassin pretending to be a "battered housewife" who needs Mike to find her husband comes to mind, as does Harlan and the nerdy "auditor" who is a good enough killer to pose a challenge to Mike in hand-to-hand.]]
** Michael lampshades that the Coast Guard is generally seen as not very powerful. He then explains why this is not truly so.
-->Most people don't think the Coast Guard as being particularly well-armed. Most people are wrong. A Coast Guard patrol boat carries three .50-caliber M2 Browning machine guns and a 25-millimeter cannon, which means it can take out anything short of a battleship.
* ''Series/BabylonFive'' episode "Ceremonies of Light and Dark". Marcus the Ranger is looking for information on some crooks who have kidnapped his friend Delenn. He joins a poker game at a tough bar in down-below and asks his contacts in the criminal underworld if they have any information to share. They decline, and ask why they should help him with this.
-->'''Marcus:''' [[BadassBoast Because if you don't, in five minutes, I'll be the only one at this table still standing.]] ''(they all laugh)'' [[NotHyperbole Five minutes after that, I'll be the only one in this room still standing.]] ''(they all stand up and glower over him; cut to commercial)''
** When we come back from commercial, Marcus is holding the beaten and bloodied last person from the entire room of thugs who isn't quite unconscious yet, who is quickly blubbering out that he doesn't know anything anyways, before collapsing into unconsciousness. An exasperated Marcus complains to no-one in particular, "[[PrecisionFStrike Bugger!]] [[Funny/BabylonFive Now I have to wait for someone to wake up!]]" He then is surprised when someone else comes into the bar: Lennier, the mousy, quiet, inoffensive diplomatic aide to the kidnapped Delenn. When Marcus grabs Lennier during their discussion, Lennier ''[[NeckLift picks him up by the neck]]'' and calmly reminds Marcus not to underestimate him. Marcus, who has just kicked the crap out of several dozen criminal thugs and assorted underworld hard-cases, thus proving his badassitude beyond doubt, is forced to back down--to another character whose badassitude is perhaps even ''more'' underestimated. (Of course, a few moments later another thug finally wakes up, and out of fear, gives Marcus the information he wanted.)
--->'''Marcus:''' You see? [[UsefulNotes/AlCapone You can get more with a kind word and a 2x4 than you can with just a kind word.]] Please, continue.
*** As might be expected from the above example, Lennier is also prone to this. During the first season, his fighting skill is a surprise to the audience, but once it's established, he continues to use it to surprise other characters.
* On one episode of ''Series/MagnumPI'', a Chinese assassin is asking a big hairy sailor where the MacGuffin is hidden. The Chinese assassin is an insignificant looking fellow with glasses. But when the bargaining becomes heated, the assassin kills the sailor with his bare hands in half a second and isn't even breathing hard.
** In another episode, Higgins goes off to an island on a camping trip with some boys from juvenile in a rehab program. They mutiny, but find out that Higgins is a RetiredBadass.
* Series/{{Chuck}} does this a lot to enemy agents who don't know what he is - his [[CurbStompBattle fight scene]] in "Chuck Versus the Beard" is a prime example.
* Caine on ''Series/KungFu'' is always underestimated by people who end up getting their ass kicked by him.
* Pretty much the entire point behind ''TheSarahConnorChronicles''' Cameron. As the show's producers pointed out, and was demonstrated throughout the series, people ''do not'' expect a [[CuteBruiser slender, cute, harmless-looking girl who looks like she's not even out of her teens]] to be a [[RobotGirl cold, implacable and utterly lethal killing machine.]]
* Happens occasionally to Dr. Daniel Jackson of ''Series/StargateSG1''. In one particular instance, someone called him a geek while he was under the influence of a physically enhancing alien device. This device also increased aggression and impulsiveness (Dr. Jackson is not usually a hothead). It... didn't end well for said someone.
** Also happened to Carter on occasion, due to her being an attractive woman. In particular, in the episode "The Warrior", a group of free Jaffa are disappointed by the Earth-based weapons they have been provided so O'Neill has Carter demonstrate how effective the weapons are. You can see the patronizing expressions as the Jaffa doubt both the weapons and the female's shooting abilities. Needless to say, Carter proved them wrong on both accounts.
-->'''O'Neill:''' This [Jaffa staff weapon] is a weapon of terror; it's made to ''[[WeaponForIntimidation intimidate]]'' the enemy. This [Earth P90] is a weapon of war; it's made to ''kill'' your enemy.
*** Ba'al, as a PoliticallyIncorrectVillain, insults Carter's intelligence '''REPEATEDLY''', even after she's saved the world a few times. After she slugged him in the face, though, he seems to have wised up.
* How often do the bad guys of Series/TwentyFour think they've got enough security to protect themselves from Jack Bauer?
* ''Series/{{NCIS}}'':
** [=McGee=]. Most people realize that being a trained Federal agent makes you dangerous. Just, [[TemptingFate how dangerous could the team computer geek be?]] Then he starts threatening people, and [=McGee=] is actually [[OhCrap pretty scary when he gets angry...]]
** Also, if you get any ideas about going after Abby... She can kill you and not leave any forensic evidence.
* ''Series/DoctorWho''. "Oh look, here comes this weirdo in stupid clothing. He couldn't possibly be that smart... how dangerous could he be?" Just... look him up.
** The double episode [[Recap/DoctorWhoS29E8HumanNature "Human Nature"]]/[[Recap/DoctorWhoS29E9TheFamilyOfBlood "The Family of Blood"]] involves a family of short-lived aliens named the Blood Family chasing him in order to consume him and gain immortality. The Doctor initially tries to escape from them by sealing his alien self while he turns human with his companion Martha as the one in charge of his former self. The Blood Family then goes after them, killing several people in the process and bombing a village to force the Doctor to come back. When it finally happen, an infuriated Doctor easily [[OutGambitted Out Gambits]] them and punishes them by putting them in various AndIMustScream situations that [[BeCarefulWhatYouWishFor specifically grant them eternal life in the process]]. They then [[OhCrap realize]] he wasn't running from them because he was ''afraid'' of them... but because he was afraid of [[BewareTheNiceOnes what he could do to them]].
** "[[AC:Subject is unarmed]]." "[[ArmCannon Ya think?]]" [[spoiler:This was said to an Auton Rory Pond, a nurse who is one of the most hardcore beings in the universe.]] [[Recap/DoctorWhoS32E7AGoodManGoesToWar And the Cybermen would also later discover that when he asks a question, best not push him to repeat it.]]
** Daleks have underestimated companion badassery before. "[[BatterUp Who are you calling small]]!?" They've also been on the ''receiving'' end of this Trope before. "[[TemptingFate What're you going to, sucker me to death?]]"
** "[[Recap/DoctorWhoS33E12NightmareInSilver Nightmare in Silver]]" has a harmless dwarf named Porridge whose primary job is to play chess while hiding under the table, manipulating an empty Cyberman's arms. At the end, it turns out that his real name is Ludens Nimrod Kendrick Cord Longstaff XLI and that he's the ''emperor of a thousand galaxies''. Sure, it's just a title, but his flagship has been hanging in orbit all this time, and the fact that it doesn't appear to have escort ships implies that it ''doesn't need them''. He can also trigger a planet-destroying bomb by simply reciting his full name in front of it.
* How much of a threat can a [[SquishyWizard gangly]], [[{{Dojikko}} clumsy]] [[BeleagueredAssistant servant]] be? Well, quite a bit if your name is Series/{{Merlin}}!
* Happens a lot to Mia in ''Series/HitAndMiss'', as she's a [[OldFriendNewGender trans-gender]] [[ProfessionalKiller hitwoman]].
* Nick Burkhardt from {{Grimm}} is subject to this a lot, like when a group of coyotls thinks he and Hank are just two cops with no idea what they are getting themselves into in addition to being out numbered, or in the rare instance where he gets to pull this on someone who knew he was a Grimm when the Reaper dispatcher sends ''two'' Reapers to catch him by surprise, only to get [[LosingYourHead a rather disturbing package in the mail]].
** This can be said of pretty much all Grimms. The pilot has Nick's aunt Marie showing up, in the final stages of cancer, looking like everybody's favorite grandma. She proceeds to kill a Hässlich Reaper with his own scythe. Even when lying in a hospital bed and approached by Munroe (who's not violent, normally), she opens her eyes and tells him to do his worst. She even identifies him as a Blutbad without him even [[GameFace wogeing]]. The trend continues with Nick's mom and Trubel. On the Wesen side, this can also apply to many, especially since not all of them appear imposing when not woged. Munroe is tall and in a fairly good shape, but he's vegetarian, speaks fairly softly, and wears sweaters. He's the last guy you expect to turn rip your arm off if you really piss him off. Then again, he used to be pretty violent in his youth.
* ''Series/{{Farscape}}'':
** John Crichton is a human from earth--a planet that hasn't even been to its ''own moon'' in almost 30 years at the time the series started--who in early episodes is constantly dealing with the scorn of the more "advanced" members of Moya's crew. And he saves their asses ''every. Single. Time.'' By the end of the first season he's finally earned their respect and friendship. And then it's time for him to do the same with his enemies:
** Crais spent almost a cycle trying to capture him before Scorpius finally gets his hands on him purely by chance. Crais's failure to bring Moya in didn't exactly sit well and made him something of a laughingstock. Then Scorpius found out first hand just ''how'' dangerous and resourceful Crichton is.
** GenreSavvy that he is, Scorpius was less likely to underestimate Crichton, but even then John still had his moments where he took him by surprise. Grayza, on the other hand, was completely incapable of recognizing the threat Crichton actually posed. ''Especially'' when the rest of the galaxy was pointing and laughing at the Peacekeepers' inability to recapture Moya.
* This gets deconstructed in ''Series/KamenRiderWizard''. One of the villains is a quirky character by the name of Sora who manages to be an annoyance to the other villains, including the BigBad Wiseman once he frees a rather destructive Phantom. Almost everyone underestimates Sora's true potential and just consider him write him off as "that annoying Phantom". Heck, even the main character, Haruto, began to underestimate him. At that point, we find out that, yes, there's more to Sora than meets the eye. [[spoiler:He was a serial killer prior to being a Phantom and has his sights on the Philosopher's Stone, a MacGuffin that the BigBad has in his possession. Once it's made clear he's after the stone, [[EvilVsEvil The Wiseman tries everything in his power to kick his ass]], though leaves him just kicking, underestimating him. It becomes Wiseman's hubris as Gremlin, on his second attempt, snatches a weapon from him and kills him with it, then steals the role of BigBad]]. Bottom line: Never underestimate the quirky Phantom, or else everyone is screwed.
** This is something that the BigBad had a case of ''twice''. The only reason his plans were foiled in the first place was because [[spoiler:he didn't account for Nitoh, a BigEater, unleashing his Phantom, an even ''bigger'' eater to consume all the Mana he needed to execute his plan. You can say that underestimating badassery is a FatalFlaw for him]].
* ''Series/PersonOfInterest'' has thugs constantly underestimating Reese due to him [[BadassInANiceSuit wearing nice suits]] and working alone. Half of these encounters only show the thugs getting ready to attack and later Reese walking away from a pile of groaning men.
* Season 3 of ''Series/{{Justified}}'' is built around this trope. Detroit mobster Robert Quarles repeatedly underestimates just how smart local gangster [[MagnificentBastard Boyd Crowder]] is. Boyd, for his part, expects that Quarles being a FishOutOfWater will be completely ineffective in Harlan County. He's right, but what he doesn't take into account is just how [[{{Badass}} physically dangerous]] Quarles can become when cornered.
** Season 4 gives us Bob, a pudgy constable (a law enforcement position that pays almost nothing and has no real authority) who is a constant ButtMonkey and is played by ''Creator/PattonOswalt''. While most people do not take him seriously, GenreSavvy characters remember that back in elementary school Bob hit a bully in the head with a hammer and put the kid in a comma. When two drunk {{Corrupt Hick}}s take start firing their rifles at Bob, they discover that Bob has an automatic assault rifle in his car. A mobster captures Bob and tortures him for information but FailedASpotCheck and does not realize that Bob carries a hidden knife on him at all times. Bob simply waits for the mobster to drop his guard and then fatally stabs him in the leg. In the confrontation at the high school, an injured Bob is fully prepared to back up Raylan in a LastStand gunfight against a dozen mobsters.
* In ''Series/{{Supernatural}}'', no matter how many monsters, demons, or other enemies the Winchesters have killed, they're almost always underestimated by whatever enemy they're facing. One notable exception is Crowley.
* In ''Series/AgentCarter'', Peggy's coworkers and superiors are all genuinely convinced that behind her bluster Peggy is just another fragile EnglishRose who needs to be protected because she hasn't "grown up" and "learned her place" as a woman. As Peggy points out in the penultimate episode everyone ignores her unless she has coffee or reports because they all think of her as a "stray kitten" in need of shelter or a "secretary turned damsel" in need of protection. Thompson himself only realizes that Peggy is quite the badass when he finally sees her pick up a machine gun and start shooting people alongside her war buddies the Howling Commandos.

* KennyRogers' "Coward of the County" - [[TheSoCalledCoward a man who took an oath]] to never resort to violence, comes home and discovers that three men had gang-raped his wife. He tracks them down to the bar they were drinking at. One goes to confront him and he turns right around and, as they laugh, walks back to the front door. Then he locks it so they won't be able to run away from the aggression he's been bottling up for 20 years. When he's done, not one of them is still standing.
** He then stands there and apologises to the soul of his dead father for not being strong enough to walk away from this one.

[[folder:Professional wrestling]]
* The only Canadian Wrestling Revolution women's champion, Wrestling/SaraDelRey, had reason to be confident in her abilities, but not enough to call a match against The Super hardcore Anime(aka, [=LuFisto=]) easy, much less a title defense. [=LuFisto=] was in earshot and immediately interrupted Del Rey's promo to call her out.
* In Wrestling/{{N|ational Wrestling Alliance}}WA Ring Warriors, Sienna Duvall relished at the chance to beat Su Yung, whom she viewed as a "diva" due to training in the Wrestling/{{WWE}} revived FCW. [[Wrestling/BlackRose La Rosa Negra]], who was already in a prolonged feud with Duvall, had little to say about Yung, just told Duvall to remember ''she'' was not a diva. After La Rosa initially brushed Yung aside though Su ended up becoming the top contender to her title and one of her most respected adversaries (though Yung's big moment was [[HarsherInHindsight slightly spoiled]] by the champ [[DontTryThisAtHome actually being hospitalized from it]])
* Wrestling/CheerleaderMelissa did not think much of Wrestling/IvelisseVelez, whom she had to defend her women's championship against when Pro Wrestling Revolution sent her to Puerto Rico to get them more exposure with the World Wrestling League and made this feeling clear by beating her all around the ring and even canceling what would have been a successful pin to punish her some more. But Vélez rallied and ended up pinning Melissa for the title belt. True, Ivelisse Vélez was only champion for three weeks, but in that time she successfully retained against Melissa again before she finally learned to take Vélez more seriously.[[/folder]]

[[folder:Tabletop games]]
* In ''TabletopGame/{{Traveller}}'' one of the main reasons the Terran Confederation defeated the Vilani Imperium was that the Vilani, at first didn't think much of Terra and effectively thought of themselves as trying to "arrest" it rather then trying to "conquer" it. They found out that [[HumansAreWarriors Terrans were warriors]].
* Happens absurdly often in ''TabletopGame/{{Warhammer 40000}}'', to the point where one wonders how these individuals have managed to survive for so long considering they tend to die horribly after severely underestimating their opponent. Examples include but are ''definitely'' not limited to Imperial Guard thinking that Orks are mindless brutes, Orks thinking Imperial Guard are just skwishy humies, Space Marines thinking filthy Eldar are no match for their zeal, Eldar thinking Space Marines are foolish primitives, everyone else thinking Necrons are just machines, Necrons thinking everyone else is just defenseless food... it happens a lot, is what I'm saying.
** The most ironic example is Literature/CiaphasCain, who honestly believes he's an abject coward. Except events and his own better nature keep conspiring to make him a hero. Despite his claims, he is genuinely brave on more than one occasion. At one point, he tries desperately to get back to an isolated friend who's about to be overrun, and blames it on some sort of head injury.
** It's rather rare to underestimate a Space Marine, but a squad of Orks including their gigantic Warboss saw an unarmed Space Marine with broken armour digging his way out of a pile of rubble. Thinking this is going to be an easy skull on his boss pole, the Warboss and his boyz attack. Rather than being a quick kill, the Space Marine instead charges into the fray and is killing Orks per second with his barehands. It finally ends when the Space Marine hoists the Warboss up and yanks out his heart. This is the first appearance of Mephiston, the Blood Angel's Lord of Death.
* A common meta example in ''TabletopGame/VampireTheMasquerade'' - often, many fights are between the player characters and human gangbangers who don't know that the people in front of them can, among other things, punch through walls, [[ImmuneToBullets take a shotgun blast to the face]], outrun a high-speed train or swing a longsword with one hand. And how the players ''love it''.
* As a general example, {{NPC}}s have an alarming tendency to underestimate the player characters' ability to get the job done.

[[folder:Video Games]]
* The Organization XIII elite assassin and second strongest member of the organization, Axel is underestimated by many characters in ''Franchise/KingdomHearts''. This always turned out to be their worst (and often last) mistakes. All the Organization members,except Lexaeus, who were sent to Castle Oblivion, made underestimated him. Axel tricked them all and killed them one by one, by both direct and indirect means.
** Xemnas, the leader of Organization XIII, and rest of the remaining members of the organization underestimated Axel, after his treachery. He alone destroyed the biggest part of the organization's army and paved the path of their fall.
** The main villain of the franchise, Master Xenahort, did not take note of his return in his human form, eventually allowing him to spoil the evil genius' plan.
** Master Xehanort underestimated Master Aqua, which was why his first plan failed.
* You'd be surprised how many people think they can take on [[{{Badass}} Shepard]] and his/her BadassCrew, even after s/he is FamedInStory, in ''VideoGame/MassEffect2''. (It never ends well for them).
** For example, Jedore, the leader of the Blue Suns on Korlus:
-->'''Jedore''': There are three of them. THREE! Anything can be killed if you do your damn jobs!
** During the mission to track down Morinth, a pair of turian muggers [[MuggingTheMonster are convinced Shepard is just a puny human. Beatdowns ensue.]]
** During the same mission Shepard can order a turian to stop harassing an asari. If Shepard is female, [[MuggingTheMonster the turian will even make an advance on her.]] No matter the gender, it ends with said turian being thrown across the room.
** Despite ''knowing'' that Wrex, [[AsskickingEqualsAuthority the most powerful]] [[ProudWarriorRaceGuy krogan on Tuchanka,]] has nothing but respect for Shepard, that Shepard has the balls (regardless of gender) to ''headbutt'' a krogan chieftain to [[ShutUpHannibal get him to shut up]] (a species strong enough to snap a human's neck by backhanding them), and has personally witnessed Shepard and buddies not only survive but possibly kill [[spoiler: a thresher maw]] on ''foot'', something that has not been done in centuries (and the last time was by Wrex), said aforementioned chieftain ''still'' thinks he can take Shepard in a fight.
** In the ''Arrival'' DLC, Shepard is captured and sedated by an indoctrinated scientist, who has him/her locked up with a small army of indoctrinated soldiers outside. This...doesn't work out.
-->'''Project Guard:''' ''[[CurbStompBattle Shepard is tearing us apart!]]''
** Shepard was the last person for who knows how long to kill a Reaper. The Reapers and the Collectors still believe him/her to be just one person... [[spoiler: at least until the end of ME 2.]]
--->'''Garrus:''' ''Honestly? The Collectors killed you once and all it did is piss you off. I can't imagine they'll stop you this time.''
*** And Harbinger has actually acknowledged that s/he is disrupting their plans. Coming from a member of a race of [[NighInvulnerability ultra powerful]] [[EldritchAbomination Cthulhu-esque]] starships, that is SERIOUS badass cred.
--->'''Harbinger:''' [[DidYouJustFlipOffCthulhu Shepard, you have become an annoyance.]]
** The Illusive Man, [[spoiler:even after being indoctrinated by the Reapers,]] [[WorthyOpponent has a great deal of respect for Shepard.]] His underling Kai Leng, on the other hand, ignores his advice on how dangerous Shepard can be. [[spoiler:It ends badly for Kai Leng]].
** Less ''destructively'', Vega challenges you to spar when you get the Normandy in ''3'', on the logic that you're just as human as he is. After the opening to ''2'', as a result of which you're 30% cybernetics and able to wield shotguns and sniper rifles with enough recoil to break a normal human's arm...yeah, you're not ''quite'' as human as he is, and despite Vega's massive muscle development, it's almost certainly going to end with him getting flipped, quite possibly by the comparatively slim female Shepard.
* In ''VideoGame/DragonAgeOrigins'', there are only two [[BadassArmy Grey Wardens]] remaining. One is you, the other one is in your party. Everybody still thinks they got a chance against you. Lampshaded by a guard after witnessing you fight:
-->'''Sergeant Kylon:''' ''And people actually voluntarily attack you. [[TooDumbToLive Are they just stupid?]]''
** In [[VideoGame/DragonAgeII the sequel]], this tends to happen as well, despite the entire point of the start of the game being about increasing your reputation/infamy. You still get people thinking you're "all hype" even after you get to Act 2, wherein you've reclaimed your family's noble status and bought back your ancestral home through acts of sheer heroism - specifically delving into parts of the Deep Roads that makes everyone short of the Legion of the Dead soil their armor - and have everyone up to [[ProudWarriorRaceGuy the Arishok]] respecting you... Or at least having a "growing lack of disgust" for you. The fact that anything short of an entire army is willing to stand up to you and your comrades by Act 3 is the height of foolishness.
* In the ''VideoGame/{{Fable}}'' series, even after the history of superhuman exploits you have well into the game, common thugs and bandits will still voluntarily attack you. This is particularly TooDumbToLive-ish in Fable 3, where people will attack you when you're ''King'', despite knowing of your Badass lineage and the fact that you are the only thing capable of saving Albion from certain doom.
* ''VideoGame/AssassinsCreedII'': Likewise for Duccio de Luca picking a fight with Ezio Auditore da Firenze ''thirty years after'' Ezio publicly beat him for infidelity against Ezio's sister. The reason Duccio dares to do so? He's got a few ''unarmed'' thugs for muscle, while Ezio's alone. Veers into TooDumbToLive though, that Ezio by now was the man who fought off the would-be killers of Lorenzo de' Medici, participated in the Forli succession conflict, killed [[TheFundamentalist Girolamo Savanarola]], fought the Borgia family guards at the bridge to the Vatican district, and even openly took to the streets to drive Cesare Borgia from Rome� ''all'' of these incidents being in public, with witnesses, and Ezio wearing the Assassin Robes. On top of that, before this Ezio was (even after his exile from Florence) had been a recognized absentee lord of the castle-town of Monteriggioni, making him a semi-public figure.
* ''VideoGame/MegaManX'' suffers from this quite a few times. Being a centuries-old "robotic relic" who is also a TechnicalPacifist, many reploids think [[TooDumbToLive he'd be a cinch to defeat]] despite the fact he's a famous Maverick Hunter. They're more than a little surprised when he destroys them.
** ''The Day of Sigma'' OVA basically centers around Sigma vastly underestimating X.
** Many ''VideoGame/MegaManZero'' bosses mock Zero's "Legendary Hero" status and the fact that he was out of commission for about 100 years since the ''X'' era. How wrong they are.
* ''VideoGame/{{Touhou}}'' characters never seem to realize that fighting Reimu or Marisa is a '''bad idea'''. Considering the former can make herself completely invincible at will, the latter can obliterate continents, and both of them have fought and won against some of the most horrifically powerful beings in existence, it is no wonder the string of pathetically weak individuals that keep challenging them to fights don't exactly leave unscathed.
* The SuperMarioBros As [[SuperPaperMario Dimentio]] found out the hard way, Luigi is [[NobodyCallsMeChicken not a pushover]], but the brothers [[BashBrothers working together]] get underestimated quite a bit... And then the villains get beaten very badly.
* Thugs treat {{Nightwing}}, ComicBook/{{Robin}}, and ComicBook/{{Catwoman}} this way in ''VideoGame/BatmanArkhamCity''. After all, Catwoman's just a ''girl'', Robin's JustAKid, and Nightwing... wait, who the hell is Nightwing? As expected, their cavalier attitude [[OhCrap doesn't last long]].
* A rather interesting example in VampireTheMasqueradeBloodlines: for most of the game, all of your enemies underestimate the [[DudeWheresMyRespect "newbie vampire"]]. It's semi-subverted near the end when everyone seems to realize "holy cow, how is this days-old vampire surviving all of these suicide missions?!" By that point, half of the Elder vampires want you on their side. The other half, sadly, see you as a threat and fall back into this trope by trying to kill you.
** Potentially a JustifiedTrope. The relative power of vampires is usually a combination of generation and the amount of time since being embraced. Typically, the player character would be expected to be thirteenth generation, at best, which used to be believed to be the weakest possible generation for a vampire for most of the setting's timeline. The blood points at character creation indicates the player is an eighth generation vampire (although this is never explicitly mentioned). It has been over 700 years since it was common for newly embraced vampires to be eighth generation, so it's hardly surprising there is a tendency to underestimate them.
* In the ''VideoGame/{{Civilization}}'' games, the NPC leaders will often make disparaging comments such as "your army is the laughinstock of the world" if you happen to have a smaller military than they do. They tend to fail to take into account things like technological advances.
** This also happens in ''GalacticCivilizations'', despite the designers claiming that their AI is markedly superior to that of other 4X games. A computer player may have a bigger fleet than you and may even be ''slightly'' more advanced but will completely discount your industrial capacity. What this means is that you can build a fleet ''twice'' the size of his in the time it takes him to get his fleet to your planets (and computer planets are notorious for declaring war first and preparing for it after).
* In ''VideoGame/TheElderScrollsVSkyrim'', one would think that a memo would have been sent to all of the Nine Holds warning ''everyone'' not to [[BullyingADragon threaten]] the Dragonborn, who routinely fights ''Dragons'' single-handedly. They generally learn their error within a few moments of hearing '''"[[BlownAcrossTheRoom FUS RO DAH!]]"'''
** Taken to an extreme by the Thalmor, who despite having the military strength to threaten the Empire, only ever bother to send up to 3 mooks after you at a time, even though they potentially may have suffered dozens of casualties at your hands.
* ''VideoGame/TheGodfather 2'': Every one of the enemy mob bosses you meet talks smack to you, with Michael himself joining in at times. Regrettably, there's no EnemyChatter for you to get the satisfaction of hearing them take their words back as you kill them off.
* The Exile in ''VideoGame/KnightsOfTheOldRepublicIITheSithLords'' gets this a ''lot'' for someone whose status as a Jedi Knight and ex-war general is common knowledge. Early on in the game, your party is being held under arrest on Telos and a bounty hunter breaks into your cell to try and take you in to collect on a bounty. Because it's not as if a Jedi Knight has the power of the ''Force'' or anything, ri--...oh wait...
** Inverted in ''one'' occasion when s/he's StormingThecastle with a pair of Mooks who run away after they saw you kill a lot of them. One of the possible answer to that is aproximativly:
-->The Exile: finaly someone's sane. Run while you can
* In ''VideoGame/TheForceUnleashed'', General Rahm Kota ''seriously'' underestimated Starkiller in their first meeting.
--> Kota: A boy? ''Months'' of attacking Imperial targets, and Vader sends a ''boy'' to fight ''me''?!
* In the backstory of ''VideoGame/StarTrekOnline'', Ja'rod, son of Torg, a Klingon Defense Force officer and a minor nobleman, was on vacation when a trio of Undine infiltrators attempted to KillAndReplace him. He killed two of them and tortured the third into revealing its species' EvilPlan. For reference, the Undine (also known as Species 8472), as large, three-legged creatures who have engineered their bodies to be powerful bioweapons. Even a scratch from an Undine is a death sentence, as its cells will spread through your body like cancer in a matter of minutes.
* This trope is twisted in the ''VideoGame/BlazBlue'' series in the sense that the underestimating is on a ''tactical'' level than a physical one. While one could easily chalk up Makoto as a SpannerInTheWorks[[spoiler: due to her effing up Hazama's plans in ''Slight Hope'']], she was also conducting a survey of the Ibukido ruins on Hazama's orders, gathered information during her trip to [[spoiler:a parallel]] Kagutsuchi, and used that information to reshape her plans - you know, the things an Intelligence officer ''should'' be doing. The reason it counts as this trope is simple: not only is Hazama an extracontinuual entity who witnessed multiple timelines, but in every one of them Makoto was his ''lieutenant'', meaning that if he was competent at his job as her Captain, there is no excuse for him to not know better. [[spoiler:In fact, the mission to Ibukido sealed a StableTimeLoop he was trying to destroy by killing her in a UriahGambit, and that mistake continues to find new and inventive ways to haunt him. By the end of ''Chronophantasma'', [[DisasterDominoes his own mistake eventually costs him]] ''[[KilledOffForReal everything]]''.]]

[[folder:Web Comics]]
* ''Webcomic/GirlGenius'': This happens with a significant number of characters.
** Gilgamesh Wulfenbach. [[http://www.girlgeniusonline.com/comic.php?date=20071128 Check]] [[http://www.girlgeniusonline.com/comic.php?date=20080303 yourself.]] Incidentally, this also happens to be his BerserkButton, making it an even bigger mistake than it usually is.
** Gilgamesh had that trope reversed on him later on, not realizing that Vole was holding back to avoid seriously hurting the Baron's son. [[spoiler:However, [[http://www.girlgeniusonline.com/comic.php?date=20110727 he is no longer worried about that.]]]] [[http://www.girlgeniusonline.com/comic.php?date=20110815 The end of this fight]] also makes him one of the very few people who managed to ''scare a Jäger''.
** Later, Tarvek happens upon a crying woman cradling the bodies of two dead animals that she failed to save. They are attacked again. [[http://www.girlgeniusonline.com/comic.php?date=20120611 This happens.]] He apparently didn't learn though as five minutes later he needs to be [[http://www.girlgeniusonline.com/comic.php?date=20120622 reminded.]]
** How dangerous could [[BattleButler Gil's valet]] be? First [[http://www.girlgeniusonline.com/comic.php?date=20070101#.VEqg__nF8YM Bangladesh DuPree]] and then [[http://www.girlgeniusonline.com/comic.php?date=20100827#.VEqhTPnF8YM Boris Dolokov]] find out.
** Zola makes the mistake of stabbing someone the apparently-ordinary Airman Higgs was just ''starting'' to like, prompting a truly EPIC beatdown.
** And of course, who would ever think a fluffy white cat was an evil mastermind?
** Even the title character frequently gets underestimated, though she also has almost as many problems with people OVERestimating her and reacting accordingly.
* ''Webcomic/YetAnotherFantasyGamerComic'': "You know what we pirates do with naked tied-up women, don't you?" SMACK. "Underestimate them, apparently."
* ''Webcomic/TalesOfTheQuestor'': Quentyn gets this a lot when he first starts out. Chances are it'll happen again; he does, after all, look like an animate plush toy...
* ''Webcomic/{{Erfworld}}'': As the quote on the quotes page indicates, Parson Gotti is subjected to this a lot, mainly because, coming from Earth to, well, Erf, he doesn't know anything the [[MaryTzu "perfect warlord"]] should know. [[MagnificentBastard They get enlightened]]. [[CrowningMomentOfAwesome Forcibly.]] Apparently, Rules-Lawyering is the greatest ability a warlord on Erf can possess.
* ''Webcomic/TheOrderOfTheStick'':
** [[http://www.giantitp.com/comics/oots0830.html Tsukiko assumed she could threaten Redcloak to his face, figuring he was the spineless wimp Xykon always treated him as]]. Further boosting her confidence was her belief that Xykon would side with her over Redcloak (he probably would too, if only to cheese off Redcloak, but he doesn't have any emotional investment beyond that), as well as several other advantages ranging from her ghoul entourage, her massive spell selection, and her comparative advantage in terms of teleport spells. Instead, [[spoiler:Redcloak proceeds to take control of her wights, counter all her spells, block her teleportation, give her a TheReasonYouSuckSpeech, and have the wights kill her.]]
** Xykon runs into this a lot. Most people who meet or see him for the first time assume that, as a "walking villainy cliché", he must be very easy to get rid of. And while Xykon is in no hurry to prove them wrong, he's incredibly powerful and devious. Both Roy and Vaarsuvius thought they could take on the lich single-handedly, and nearly paid the price. [[spoiler:Roy died in his second attempt, [[DeathIsCheap but got better]].]] So far, the only real threat to his existence was the ghost-martyr of Soon Kim.

[[folder:Web Original]]
* Jade Sinclair (Generator) of the ''Literature/WhateleyUniverse'' gets this a lot, because she's a petite, pretty teenager who looks like a ten year old Japanese girl. When she is attacked by Bloodwolf and Maggot and Killstench simultaneously, she knocks two out (breaking one's jaw) and takes out the unstoppable Bloodwolf (who can heal from any injury) by nailing him to a tree. With railroad spikes.
* The protagonist of ''Literature/{{Worm}}'' is a skinny teenage girl whose only power is the [[WhatKindOfLamePowerIsHeartAnyway ability to control bugs.]] This is in a world where gamebreaking superpowers are common. '''[[CombatPragmatist Do]] [[EyeScream not]] [[FromNobodyToNightmare underestimate]] [[BewareTheNiceOnes her.]]'''
** A RunningGag in the comments section is that pretty much everyone's reactions to Skitter is "Meh, I could take her." One person noted (Somewhat inaccurately), That there were only ''two'' exceptions to this in the ''entire story'', namely Sundancer and Citrine. Amusingly, Citrine is one of the few capes at that point in the story that Skitter is nervous about fighting (If not outright ''afraid''), thanks to her ability to [[spoiler: turn people's powers against themselves]].
*** And then [[spoiler:Jack Slash]] [[AscendedMeme actually says exactly that in story]].
** Eventually, the PRT learns not to do this: they specifically say, "Look, take our rankings for her, and treat her as though she were two rankings higher ''across the board''." They decide to treat her as though she were a Brute, a Breaker, and ''especially'' a Trump of some degree. [[spoiler: It doesn't help much, but at least they tried...]]
* "UltimateShowdownOfUltimateDestiny" ends with [[spoiler:[[MisterRogersNeighborhood Mister Rogers]]]] as the ultimate victor. It also features UsefulNotes/AbrahamLincoln and [[{{Transformers}} Optimus Prime]] being taken out by a [[CareBears Care Bear Stare]].

[[folder:Western Animation]]
* From JusticeLeagueUnlimited: LexLuthor has just taken out the founding members of the JusticeLeague and is smirking at TheFlash.
-->'''Luthor[[spoiler: /Brainiac]]:''' Are you going to [[TemptingFate fight me]], ''boy''?
** ...Cue one of the greatest [[CrowningMomentOfAwesome Crowning Moments Of Awesome]] of the whole show.
** Batman gets this too, just like in the comics - notably from Dr. Destiny in "Only a Dream":
--->'''Dr. Destiny:''' But you're different. You don't have any special powers.
--->'''Batman:''' Oh, I have one, Johnny: I ''never'' give up.
* Also from the {{DCAU}}, elderly Bruce Wayne does this all the frickin' time on WesternAnimation/BatmanBeyond. Proof? Go to the WesternAnimation/BatmanBeyond CMOA page and find all of the Old Bruce Entries. 99.9% of those are this, the other .1% is ass-kicking resulting from this.
-->'''Jokerz Leader:''' Who do you think you're talking to, old man? We're the Jokerz!\\
'''Bruce Wayne:''' ''(dryly)'' [[PretenderDiss Sure you are.]]\\
'''Payback:''' You're a mean old man, you know that?\\
'''Bruce:''' Mm-hmm. And what are you?\\
'''Payback:''' I'm your worst nightmare!\\
'''Bruce:''' You have ''no idea'' what my nightmares are like.
** In ''WesternAnimation/BatmanBeyondReturnOfTheJoker'', Terry is contemptuously dismissed by the Joker before their final confrontation:
--->'''Joker:''' You're out of your league, [=McGinnis=]. I know every trick the original Batman and Robin knew at their peak.\\
'''Terry:''' Maybe. But you don't know a thing about me.\\
'''Joker:''' ''You?!'' What's to know?! You're a punk! A rank amateur! A costumed errand boy taking orders from a senile old man!
* This is one of the primary themes behind the ''WesternAnimation/SupermanTheAnimatedSeries'' episode "World's Finest", which brought Batman and the Joker into the picture. Both Superman and Lex Luthor see both the Joker and Batman as non-superpowered beings not worth their time and energy. By the end, Batman has scared the crap out of Luthor (something even Superman never even managed) by breaking into his penthouse, and the Joker comes closer to killing Superman than just about any other villain had previously, almost kills Luthor, takes over the mob, and almost levels a good portion of Metropolis to the ground.
* At the beginning of ''WesternAnimation/AvatarTheLastAirbender,'' Commander Zhao regards Prince Zuko as a [[WhiteSheep weak]], [[RoyalBrat bratty]] teenage punk. They get into an argument, and Zuko challenges him to a duel, which Zhao fully expects to win. Not only does Zuko [[CrowningMomentOfAwesome soundly beat him]], but he [[SwordOverHead spares his life]] as well.
** And Zhao does it again against Aang in a later episode; when warned by his former master that he is not ready to fight the Avatar, Zhao arrogantly replies "I think I can handle a child". The result? Aang makes him look like a fool by tricking him into [[NiceJobFixingItVillain destroying his own fleet]], thus defeating him ''without landing a blow''. Obviously, Zhao never learns.
** On the surface, Zuko's Uncle Iroh looks like a quirky old man who'd rather do little else besides sleep and drink tea. Of course, he's exactly that, but he's ''also'' the [[NamesToRunAwayFromReallyFast Dragon of the West]] and ''will'' kick your ass six ways from Sunday if you give him a reason to. There's more than a few of his foes that don't seem to get that.
** Long Feng saw Princess Azula as a smart and potentially dangerous teenager who was still in way over her head, believing that she would be easy to manipulate and betray. Unfortunately for him, she's actually a full-fledged MagnificentBastard who only played along with that idea before turning his own men against him with her cunning and ruthlessness.
** The sequel ''WesternAnimation/TheLegendOfKorra'' keeps in this direction: while [[TheSociopath Yakone]] wasn't exactly a poor villain (he was a dangerously skilled Bloodbender and a Crime Lord), he ''did'' underestimate Aang according to the flashbacks, mocking him and telling him he dealt with people like him before and would do it again. Apparently, he forgot Aang was the ''Avatar'', meaning a guy connected to the Spirit World and controlling all elements. So it's not that much of a surprise when, during their confrontation, Aang just went avatar state, immobilized him and took away his bending.
*** Similarly, [[spoiler:Yakone's son Tarrlok severely underestimated [[BigBad Amon]] when confronted by him and ended up with the same fate.]]
** Also from ''Legend of Korra'', [[GodOfEvil Vaatu]] disregards Wan, saying that a mere human is no match for an immortal spirit like him. He's right, [[spoiler: until Wan [[FusionDance fuses]] with Vaatu's ArchEnemy Raava and becomes the Avatar]].
** The Season 3 Episode "Long Live The Queen" has two; first, the Earth Kingdom soldiers do everything they can to restrain [[PhysicalGod Korra]], but only chain [[BadassNormal Asami]] to a loose pipe, which she proceeds to break free of with ease. The second example involves [[GodSaveUsFromTheQueen Earth Queen Hou-Ting]] and Zaheer's gang, whom she thinks are nothing more than common bounty hunters she can push around. [[spoiler: They kill her]].
* When CaptainAmerica escapes imprisonment inside the Skrulls' ship in ''WesternAnimation/AvengersEarthsMightiestHeroes'', the Skrull commander immediately assumes there is no need to bother because "[[GenreBlind This man isn't a threat]]. [[TooDumbToLive There is nothing special about him]]." A few minutes later, Cap has freed all prisoners onboard, convinced all of them (some of them being villains) to team up and led them to a ship which they use to escape. The Super-Skrull even lampshades his commander's stupidity and tries to kill Captain America, declaring him too dangerous to be left alive.
** Similarly, in ''The Deadliest Man Alive'', [[spoiler:RedHulk pulled out a plan to forcibly make the Hulk act even more violent than he usually does in order to get rid of him, be accepted as a replacement for him amongst the Avengers, and gradually take control of the team. When his act is revealed after a failed attempt to frame CaptainAmerica, he [[SmugSuper arrogantly mocks the Avengers]], calling them a joke and gloating about how he could have easily taken over had he not been discovered... then IronMan reveals he [[GenreSavvy never trusted him in the first place]] and put a failsafe in his ID card to neutralize him should he be a traitor. [[CrowningMomentOfAwesome Next second, Red Hulk is immobilized by the failsafe and forcibly turned back into his human alter ego, General Ross.]]]]
* WesternAnimation/{{Ben 10}}: the title protagonist tends to get this a lot, especially in the original show, because he is 1) a human in a universe where his species is considered primitive and 2) a kid who happened to end up accidentally in charge of the most powerful weapon in the universe which he barely understands. However, he turns out to be quite good at using it, and only get better with time. Eventually, the villains who already clashed with him before are GenreSavvy enough to warn their minions about not underestimating him (Ghostfreak once beat up his [[TheDragon Dragon]] Dr Vicktor for believing Ben was not worth killing). In the sequels, however, Ben's mutiple exploits ended up making him a LivingLegend, and most villains are careful about not underestimating him.
** One of the most noticable cases of this trope is Simian, an Arachnichimp ConMan who wrongly assumed he could easily fool Ben into doing his job for him by making up a sad story to attract his sympathy. Ben went along with it, but, by the end of the episode, we find out [[GenreSavvy he actually had started to figure out the truth around half the episode]], and ''already'' OutGambitted Simian. The poor alien con man ends up finding out about that far too late, when he is already in presence of his ''very'' pissed off hirer...
** Ben himself severely underestimated [[BigBad Vilgax]]'s [[TheDragon lackey]] [[EvilGenius Psyphon]] ''twice'', seeing as Vilgax is basically TheJuggernaut, while Psyphon would almost never fight and just built tech for his master or advised him, Ben assumed he wouldn't be much of a threat once his master was absent. The first time they fight, Psyphon actually proves a challenge to ''[[SuperMode Ultimate]] [[LightningBruiser Spider-Monkey]]''; [[Ben10Omniverse the second time]], he [[DeadlyDoctor messes with his nerves]], [[BatmanGambit forcing him to go back to human form in order to not hurt anyone]]. Both times, Ben survived mostly thanks to interruption of the fight.
** Ironically, Psyphon himself underestimates [[HyperCompetentSidekick Rook]] during their first fight:
--->'''Rook''': The Body Armor is not for sell, Psyphon!
--->'''Psyphon''' (shooting at him): Oooo, I don't want to buy it! I will pry it from your lifeless body. [[NaiveNewcomer How green are you]] ?
--->(Rook dodges his EyeBeams and [[BatmanGambit tricks him into causing the whole place to collapse on him]])
--->'''Rook''': Not so green that I let a tunnel collapse on me!
** In a moment of BondVillainStupidity, Dr Psychobos assumes Ben isn't a threat to the Faction's plan... even though at this point, Ben has pretty much already become a LivingLegend who saved the Universe several times. Malware even calls him out for it.
* ''WesternAnimation/KimPossible'': Ron Stoppable is constantly considered a fool and harmless by villains...at least until he causes their lairs to blow up. The ones who really underestimated him and paid the price were the AlienInvaders that attacked the Earth in the GrandFinale, who planned to make Kim into a trophy. [[BerserkButton Big mistake]].
* A unique case of someone underestimating the potential of one of their own creations appeared in ''WesternAnimation/LiloAndStitchTheSeries'' where MadScientist Jumba believed Experiment 523 aka [[AnIcePerson Slushy]] wasn't very dangerous and only capable of making things cold, until he discovered that Slushy could [[GoneHorriblyRight take the entire island into the next ice age]].
-->'''Jumba''': It's very evil after all! [[EvilLaugh Hahahahaha!]]