[[quoteright:320:[[WesternAnimation/ClassicDisneyShorts http://static.tvtropes.org/pmwiki/pub/images/TVTFIFO.png]]]]

->''You never realized before, but your skull makes a funny "bonk" sound whenever you're inflicted with serious head trauma.''
-->-- ''Blog/{{Moonstuck}}'', [[http://woonastuck.tumblr.com/post/15694169498 this post]]

In a classic cartoon, any [[AmusingInjuries non-fatal (which is to say, just about every) head injury]] immediately results in a huge swelling the size of an orange or larger, usually pushing its pink, fleshy way through the victim's hair. Sometimes they come [[InstantBandages pre-bandaged]]. May also erupt in the exact shape of the object that caused them. Attempts to shove the lumps back into one's head will usually be answered with a lump of equal-size appearing on the other side of the head... or sometimes somewhere else entirely.

Occasionally further damage will make the lump grow into an obelisk shaped little mountain, or cause the lump to sprout another smaller lump. These can happen multiple times in a row, causing either a very tall bump, or a little cactus-like appearance.

The spherical one is more popular in {{Anime}}, whereas the mound shaped one is more popular in WesternAnimation, although both have appeared in either medium.

Unfortunately, a TruthInTelevision, as a hard hit to the head can result in a swelled bump, which, if unlucky, won't go away for a long time. Animated mediums tend to [[RuleOfFunny exaggerate this]] though.

Not to be [[IThoughtItMeant confused]] with YourHeadASplode.

----
!!Examples

[[foldercontrol]]

[[folder:Anime & Manga]]
* In the first ''Anime/AstroBoy'' anime, this happens to a ''[[RuleOfFunny telephone]]''.
* In ''Anime/{{FLCL}}'', a Cranial Eruption, rather than producing a concussion, produces a HumongousMecha, and rather [[FreudWasRight phallic]] ones at that. [[WhatDoYouMeanItWasntMadeOnDrugs It's that kind of show.]]
** Then there's guitars. Electric guitars.
* In the first episode of the resurrected ''[[MahouSenseiNegima Negima]]!'', a mishap leaves Negi with a Cranial Eruption, among other marks.
* In one episode of ''Manga/BoboboboBobobo'', Bo-Bobo hits Don Patch on the head multiple times to make him get not only a lump on his head, but multiple lumps on top of that lump. Then Bo-Bobo tries to use it as a sword of some sort. When that doesn't work, he uses a bat to whack the lumps off of Don Patch's head like a bunch of baseballs. And, like everything else in that show, this carries the disclaimer .
* This is common in ''Manga/DetectiveConan'', used whenever Conan gets whacked on the head for interrupting investigations.
* When Kenshin receives an ArmorPiercingSlap in ''RurouniKenshin'', he usually gets one of such lumps.
* In ''Caravan Kidd'', [[http://www.anymanga.com/caravan-kidd/001/001/023/ Wataru gets a HUGE lump on his head]] after ActionGirl Mian Toris had made a rather [[http://www.anymanga.com/caravan-kidd/001/001/022/ surprising landing on him...]]
** Babo, his unscrupulous boss, [[http://www.anymanga.com/caravan-kidd/001/001/032/ gets one, too]] after getting [[AnvilOnHead hit from falling aviation titanium alloy]] from a freshly-destroyed Helgebard warplane.
* In ''DrSlump'', on one page, [[http://www.mangareader.net/dr-slump/1/74 bad-boy Taro gets caught wearing shades and smoking a cigarette by the teacher...]] [[http://www.mangareader.net/dr-slump/1/75 and he himself sports a big lump on his head]] on the next page!
* It happened a couple times in ''Anime/DragonBallZ''. One example is when Goku hit Gregory the grasshopper over the head with a mallet which he was assigned to do by King Kai. In another example, Krillin is testing Goku to see if he could deflect a rock thrown at him while in Super Sayian form; it ends up hitting him on the head and a large bump appears where it hit.
** Also notable in an early episode when Goku gets hit in the head by an axe which shattered afterwards.
* Occasionally happens to the title character of ''Manga/{{Naruto}}'', especially when hit by Sakura.
** One moment has Naruto get one from a log, which also gets a bump.
* Happens to Kafuka Fuura in ''SayonaraZetsubouSensei'' in the few occasions she gets hit in the head.
* These happen occasionally in ''GalaxyFrauleinYuna'''s more light-hearted episodes. One particularly amusing case in the first OAV episode had the bump "healed" by Yuri Cube snagging it off Yuna's forehead with her chopsticks -- and immediately eating it, saying it looked tasty.
* With the abundance of {{Megaton Punch}}es, {{Armor Piercing Slap}}s and characters otherwise being reduced to ATwinkleInTheSky, it should be no surprise that this gets more than the occasional glance in ''RanmaOneHalf''.
** An amusing instance in the manga, when Happōsai's Cranial Eruption is hit by a little splash of water from the Spring of Drowned Twins. Instead of duplicating him, it duplicates his lump.
* Everytime Nami gets furious in ''Manga/OnePiece'', expect these to pop up on whoever annoyed her.
** And one cannot forget Luffy versus the [[MixAndMatchCritters Sphinx]]. When Luffy was done with it he was literally standing on the poor thing's head, atop a mountain of these.
* in ''{{Niea 7}}'', Niea gets knocked over the head by Mayuko quite a bit, leading to this. Of course, Niea [[{{jerkass}} deserves]] it ''every single time''.
* ''Manga/HidamariSketch'': Yoshinoya-sensei, after saying or doing something rather [[OneOfTheKids un-teacher-like]], is usually seen in the background of the next cut, doing the SeizaSquirm with a (often multilayered) cranial eruption while the Principal lectures her.
** Miyako also receives them fairly frequently from Sae.
** Yuno also gets one, though it's because she bumped her head on the moving truck.
* The titular character in ''CrayonShinChan'' gets hit in the head a lot by his mother which always shows an off-screen cutaway sound effect.
* These happen from time to time in MaiOtome, such as in one piece of official art in which Haruka, sparring with Shizuru during her time as a Coral, fails to block Shizuru's staff and gets hit in the head (resulting in the staff bending on impact). In MaiOtomeSifr, Lena gives one to Elliot while repelling her advances.
* ''[[Manga/KOn K-On!]]'''s Ritsu is usually the one to receive them from Mio, sometimes stacked. In the anime, the stacked version (one hit for making noise while studying is being attempted, and one for poking the sole of Yui's tingling foot) is seen shrinking back on its own.
** Yui has been on the receiving end of it once on New Year's Day at a temple... [[CompletelyMissingThePoint because she was praying for the exact things that the the band unanimously agreed that it won't pray for]].
** When Ritsu and Tsumugi hung out together for the first time without any of the others, Tsumugi asked Ritsu to hit her, taking it as a form of physical intimacy that Ritsu and Mio practice. Ritsu initially can't bring herself to do it, but Tsumugi later gets her wish after telling Ritsu that she was "a really good date", and that if she were a boy, the girls would be crawling all over her. At the end, there's a picture of her with it, captioned "Me and My Lump".
* ''Manga/StrawberryMarshmallow'': For a girl who does things that provoke people to knock her face down on the floor, Miu gets them surprisingly rarely. The first time in the manga was the result of Ana whacking her with a recorder for revealing her surname. (The analogous scene in the anime didn't have one.)
* It happens to Tulip the giant in JackToMameNoKi when Jack smashes a wedding decoration over his head.
* Happens sometimes in Manga/{{Haruhichan}}. Despite Nagato and Achakura giving this to each other, there are some episodes to which Achakura also gets this, such as hitting her head on the ceiling.
* In one episode of ''Anime/PantyAndStockingWithGarterbelt'', Stocking walks off screen with a large metal pipe in her hand in order to confront Garterbelt about what is taking him so long to make dinner. The screen shakes and you hear a few blows being exchanged between them. Stocking walks back on screen with a knot that is equally the size of her own head.
* ''Manga/{{Needless}}'' does this ''a lot'', most of the time the characters have [[RuleOfFunny bumps on top of bumps on top of bumps on top of bumps!]]
[[/folder]]

[[folder:Comic Books]]
* In ''ComicBook/LeonardLeGenie'', Basile suffers these very often, sometimes in multiple layers. In one instance, a (self-inflicted) strike with [[AnvilOnHead an anvil]] resulted in a lump larger than his head!
* Also very, very common in ''ComicBook/MortadeloYFilemon''.
* In the ''Magazine/NintendoPower'' comic ''Super Mario Adventures'', one episode has Mario tied up and injured, with a single, a double, and a triple Cranial Eruption ''growing through his hat''.
* Appears frequently in Italian DisneyComics (known as "bernoccolo"). Creator/CarlBarks's story "The Mad Chemist" has DonaldDuck hit upon a one-in-a-million chance of one turning him into a genius. Too bad they fade away in time.
[[/folder]]

[[folder:Films -- Animation]]
* In ''Disney/WreckItRalph'', Fix-It Felix receives one on his forehead, as one of the many facial injuries he receives from Calhoun hitting him (it's the sixth or seventh time he gets hit).
[[/folder]]

[[folder:Films -- Live Action]]
* In one of Creator/JackieChan kung-fu comedies, probably ''Film/DrunkenMaster'', there is a scene where the hero fights a master whose style imitates a bull -- he hits and blocks with his head, which seems impervious to any damage. Then the hero starts hitting him with a stonemason's hammer -- that doesn't kill the "bull", but creates four anime-ish round bumps too painful to touch.
[[/folder]]

[[folder:Video Games]]
* In ''VideoGame/SuperMarioWorld'', one of the world victory gags has Mario blow up the castle, only to have it launch directly into a bump-shaped hill, which then rises a little bit and sports a bandage for the rest of the game, looking like a humungous Cranial Eruption.
* In the ''VideoGame/PaperMario'' series, you can find a rare creature called a Whacka. Hitting it on the head causes it to produce (and drop) one of these. It's actually one of the best and most profitable-to-sell items in the game. Downside is, you can only get so many of these from a single wacka before it disappears forever, and there's only one in each game...
** There's also the bit about [[YouBastard the game guilt-tripping you about it]].
* In ''[[VideoGame/RavingRabbids Rayman: Raving Rabbids]]'', the entire object of one of the minigames is to give a Rabbid the biggest lump possible. After a set time of whacking him with a hammer, the lump just grows taller and taller, measuring out how many times you hit him. This is probably the most extreme example of this trope, with the lump easily growing many many times his height.
* Fourth boss in ''Super VideoGame/MeatBoy'' gets blocky ones.
* During the [[spoiler: hard mode]] ending in [[PuyoPuyo Puyo Pop]] Fever, [[http://www.youtube.com/watch?v=LwFxoGX3CZY&t=10m14s Raffine gets this after being knocked out by Ms. Accord,]] and Raffine [[EasyAmnesia ends up losing her memory about the flying cane.]]
* In the Stage 4 cutscene in ''[[VideoGame/PaRappaTheRapper Um Jammer Lammy]]'', Captain Fussenpepper gets one every time he gets hit on the head with the loose circuit board. They do not appear when he gets hit during the song though.
[[/folder]]

[[folder:Webcomics]]
* In ''Webcomic/WelcomeToTheConvenienceStore'' this is the most common injury with layers and layers of them on top of each other. First example is on the [[http://www.webtoonlive.com/webtoon/Welcome%20to%20the%20Convenience%20Store/ch1/ first page]].
* Both [[{{Sleepyhead}} Laure]] and [[TeamMom Ship Leesoo]] from ''Webcomic/TowerOfGod'' suffer from these. They are inflicted by [[HardDrinkingPartyGirl Serena]] and [[FieryRedhead Quant]] respectively.
[[/folder]]

[[folder:Western Animation]]
* Sometimes used in ''WesternAnimation/SpongebobSquarepants'', such as in one episode, where a dozen or so objects on a shelf land on Mr. Krabs' head, and then a tall lump grows from his head, located right between his eyes.
* In quite a few episodes of ''WesternAnimation/TomAndJerry''. Spike the Bulldog is probably the most common victim of this, usually while caught in the crossfire between Tom and Jerry's antics, leading into the gag where Tom sheepishly tries to push the bump down only for it to grow back. But it becomes much more frequent in the Creator/ChuckJones era.
* An amusing Cranial Eruption happens in the DonaldDuck short ''Fall Out, Fall In''. As Private Duck builds his tent, he's shot like an arrow headfirst into a tree. The resultant bump makes a dent in his helmet. (See image above.)
* These are a mainstay of WesternAnimation/LooneyTunes shorts.
** Especially ''WesternAnimation/WileECoyoteAndTheRoadRunner''... or at least, to Coyote.
** The RunningGag in the Bugs Bunny cartoon ''Rabbit's Kin'' is to offer tea and ask Pete Puma how many lumps he wants with it. Instead of dropping sugar into the drink, Bugs [[LiteralGenie clobbers him over the head until that many lumps appear.]] Averted slightly when Pete [[PaperThinDisguise disguises himself as the young bunny's mother]]. Pete is asked for lumps in her coffee, but Pete was armed with an ACME Stove Lid on her head. [[spoiler:Three guesses who had an ACME Stove Lid Lifter on himself.]]
** Subverted and played straight in ''The Wise Quacking Duck'': Offering sugar for coffee, Daffy asks Mr. Meek how many lumps his wife usually gives him. Mr. Meek takes off his hat and reveals a lump on his head. Then Daffy gives him another.
** In "Sahara Hare", Riff-Raff Sam hits his camel over the head, and as the lump grows, its hump shrinks.
* When Popeye hits a two-headed ogre in ''WesternAnimation/PopeyeTheSailorMeetsSindbadTheSailor'', the ogre gets a lump in his ''other'' head.
* This becomes a plot point in ''WesternAnimation/TheAngryBeavers''. Daggett gives himself one of these while attempting to show workers at a construction site [[KnowNothingKnowItAll how real construction is done]]. The recurring scientist characters end up mistaking Daggett for an endangered species, the "Great Horned Beaver".
* Frequently happens in ''WesternAnimation/RenAndStimpy'' almost every time someone receives a blow to the head, one example in an Adult Party cartoon episode Ren hits a duck over the head with a club causing a very tall bump to form on his head and they climb it to enter the house they are going to rob.
** The comic book played with this in the special "Masters of Time and Space" issue. Ren gets hit on the head twice, causing him to have two Cranial Eruptions. When another Ren, having just dropped in from a time warp, laughs at him, the first Ren bops his head, causing a bump to sprout from that Ren's head. This, in turn, creates a ''third'' bump on the first Ren's head.
* In ''Goofy Gymnastics'', Goofy gets one of these on the noggin after a set of chin-ups, when it's revealed that the horizontal bar was loose, and it promptly falls on his head. He even pushes the lump down and flexes his bicep, which makes it pop up there.
* Cadpig gets on in an episode of ''Disney/OneHundredAndOneDalmatians: The Series''
* This has happened to Homer in ''WesternAnimation/TheSimpsons'' on a few occasions when he gets hurt, most notably when he fell off Springfield gorge the first time he completes the fall the skateboard he was riding on hits his head producing one of these, a deleted scene reveals the second time it happens the stretcher hits his head producing a second bump.
* ''WesternAnimation/TheFlintstones''. Fred gets one for storing his bowling ball at the ''top'' of the closet.
* All the time in ''WesternAnimation/EdEddNEddy''.
* Happened quite a number of times in ''WesternAnimation/MrBogus''.
* MickeyMouse gets one in "The Grocery Boy" after an iron falls on his head. It shrinks down when Minnie kisses it.
* Carl from AquaTeenHungerForce gets a somewhat more realistic yet still hilarious case of this after one of Frylocks inventions fly's out of the house and bounces off the back of his head at top speed in the beginning of the episode. When he returns near the end, Carl now has a heavily swollen, purple/blue/green lump on the back of his head that he claims "needs to be drained 3 times a day, so his brain can think good."
[[/folder]]

[[folder:Real Life]]
* Kickboxing and UsefulNotes/MixedMartialArts can and have resulted in some pretty unbelievable injuries. [[http://www.cracked.com/blog/wp-content/uploads/2009/05/sb05ralphwhite.jpg Ralph White]] and (WARNING: Kinda horrific) [[http://www.cyrilabidi.com/fr/imagespresse/choc_grossetete.jpg Jerome Le Banner]] are two of the most notable examples, as detailed by SeanBaby in [[http://www.cracked.com/blog/the-top-eight-oh-shit-moments-in-mma/ this]] {{Website/Cracked}} article.
* Another such incident is the aftermath of a boxing match between Evander Holyfield and Hasim Rahman, in which Holyfield's headbutts caused a swelling hematoma on Rahman's forehead.
[[/folder]]
----