Expressive Hair

Either it's unconscious telekinesis or itsy-bitsy teeny-weeny muscles (or just the animators being weird!), but however it's managed, the character's hair is independently mobile and responsive to their moods. Sometimes it's nothing more than a pigtail that sticks out straight in defiance of gravity when the character's shocked or frightened, but it can go so far as fully prehensile braids that shape themselves into hearts, question marks, and other iconic forms.

See also its sister trope, Expressive Mask, and its (occasionally) more violent cousin, Prehensile Hair. Can be related to Kaleidoscope Hair if the hair changes color.

Anime and Manga

 * Alucard from Hellsing chose his form as the vampire we see, so when he gets bit on the crazy bloodlust side, his hair writhes like tentacles and get more of a jagged ourline.
 * Ranma from Ranma ½ has the "simple" extending pigtail form.
 * A Filler manga story has Genma Saotome take a hair-restoring tonic that gives him a ridiculously large, spiky hairdo (a parody of the hairstyles of Super Saiyans from Dragonball Z) when he's angry, which actually attacks the source of his anger.
 * Ma Renka in Kenichi the Mightiest Disciple has two short pigtails that droop when she's sad, stand up when she mad, and wag when she's happy!
 * in Mai-HiME has four long curls/ponytails which take on a life of their own whenever she gets angry, going so far as to manifest little snake heads at their ends or spontaneously throttle people when she's particularly upset.
 * Shiho's counterpart in Mai-Otome wears the same hairstyle but it seems somewhat less (although still expressive).
 * Arika's waist-length braids have been everything from an ant's antennae to punctuation marks to a, in addition to generally flailing about whenever she gets excited.
 * In Negima!?, an Alternate Continuity of Mahou Sensei Negima, Asuna's long ponytails are almost as expressive as Arika's braids; in the first episode alone, they stand up when she is agitated, and repeatedly formed the numerals for the number of minutes of extra sleep she wanted. And as if that weren't enough, the bells she wears in them get into the act as well, firing off like cannons when reaches a certain level of frustration. Here, being expressive is the default state of Asuna's hair, forming anything from exclamation marks and question marks to words and Cross Popping Veins.
 * A few characters in Mahoraba:
 * Natsume Kanno's hair occasionally sprouts flowers.
 * Chanohata Tamami's braids are known to rise up in anger.
 * Momono Megumi's hair antenna can be used to point or form punctuation.
 * Hana-chan in Fruits Basket, whose hair was apparently attuned to electrical signals.
 * Elizabeth in Maburaho on many occasions, as well as one expressive hair battle between Yuuna and Kuriko.
 * Sailor Moon uses this effect to make Usagi (whose name means "bunny") vaguely resemble a rabbit at comic moments. Not to mention that during transformation sequences, her odango seem to move on their own in whatever way they want, regardless of the external forces. There's even an early example of her round balls turning into detached stars for a moment.
 * Nearly every Studio Ghibli film ever made, especially Spirited Away.
 * Tomari from Kashimashi Girl Meets Girl
 * Wedding Peach
 * Parodied in Azumanga Daioh, Osaka has odd fantasies about the way Chiyo's pigtails work, e.g. when she lifts one, the other goes up too, they enable flight, they talk, and they pop off and can be replaced with new ones.
 * Also played straight on occasion.
 * Edward Elric's braid (and the rest of his body, for that matter) flares up when ever someone calls him short on Fullmetal Alchemist.
 * Mitsudomoe: Futaba's topknot wriggles during activities that require more than average brain activity (that is, when she's drawing, thinking, making a plan etc.)
 * On One Piece, Mr. 3 of Baroque Works often forms his number-three-shaped top-knot into question marks and exclamation points. For some reason, when he is about to use his Doru Doru powers, the tip sets itself on fire without the flame spreading or him feeling it.
 * And then there is Franky whose hair works as a fuel gauge and also indicates what kind of fuel he's currently on.
 * Franky can now control his hair by pressing down his nose. Considering how much Oda loves afros and mohawks, it's no surprise that this is currently all it's been used for.
 * Tenma from School Rumble has stubby not-quite-antennae sprouting from her temples which waggle when she's happy or angry. This is lampshaded in the comic once: she's feeling decidedly mixed, so one not-quite-antenna is sticking straight out, the other straight up.
 * This happens in every single Hayao Miyazaki film -- when she's angry or surprised, the female lead's hair will visibly puff up.
 * And in one movie, the male lead. He even managed to do it once with his hat.
 * The titular character in Howls Moving Castle is prone to this, though it might help that he is a Bishounen wizard.
 * Bakura and Malik in Yu-Gi-Oh!, as well as Takuma Saiou in Yu-Gi-Oh GX, get much more bizarre hairstyles when their evil sides emerge. The same thing happens with Yugi, although in his case the only change that occurs when Yami Yugi appears is that lightning-bolt-shaped strands of hair float up.
 * In the unexpectedly violent anime/manga Alien Nine, the winged hat-like alien symbiotes eventually transform themselves into consciously controllable, spike/spear/drill-forming hair, replacing a host's natural hair.
 * Ranka in Macross Frontier has startlingly mobile hair, a legacy of her quarter-Zentradi genetics.
 * Sasami in the Pretty Sammy series has two long tails that often contort and stand on end when she's stressed.
 * Princess Tutu rarely does this, but there is one comical scene when Fakir is surprised and the bangs covering his face stand straight up in shock. (Oddly enough, his ponytail doesn't do this.) Ahiru's Idiot Hair also seems to have a bit of a mind of its own at times.
 * Two notable examples in Shaman King: Ren's trademark spike of hair raises/gets taller when he gets angry. On the other hand, Ryu's pompadour (whatever state it's in) droops and raises with his mood. The most extreme example was when he realized that Lyserg had gone to another team, and his hair fell out of the pompadour instantly due to grief.
 * Himeko of Pani Poni Dash has an expressive ahoge that not only wiggles when she's happy and stands straight up when she's startled, it also occasionally form shapes like a heart or a question mark, and in the first episode even became a rainbow when she cried buckets of tears.
 * Tokyo Mew Mew: Retasu's braids do this on a few occasions, and Ichigo's pigtails also do this somewhat.
 * In Chrono Crusade (manga version) when Satella is first introduced, one of her hair antenna curves into a question mark to show her confusion over something.
 * In Axis Powers Hetalia, Yonsoo aka Korea's hair has a single strand that curls up. It's often drawn with a little face inside of the curl, so he literally has expressive hair.
 * The Italies' hair curls also do a little of this, occasionally shaping into hearts when happy or going jaggedy in shock.
 * There's also been a couple of instances where America's little ahoge will seem to emphasize his emotions as well.
 * Austria's ahoge as well, in some instances. Most notably during the Buon San Valentino strip and the Maria Theresa and the War of Austrian Succession strip.
 * Mahoro in Mahoromatic has two little sideways locks of hair that follow this trope.
 * Solty in Solty Rei has her ears, which look like thick, green versions of Mahoro's side locks, do this.
 * Hayashida's mohawk fluttering about and Noboru Yamaguchi's (for lack of a better word) pulsating afro to an extent in Cromartie High School. Hayashida's mohawk, for example, is practically its own character. When he is confused, he scratches his head, and his hair scratches his hand. And it's not even his actual hair!
 * Maka from Soul Eater has pigtails that have a life of their own when she's agitated. (At least in the anime.)
 * Ogiue from Genshiken has a spiky pigtail that sometimes stands up when she's startled.
 * Suzuna from Eyeshield 21 has an antenna-like bit of hair in the front that zeros in on anyone talking about their romantic relationships (usually denying one). Also, sports commentator "Machine Gun" Sanada has sawblade-like protrusions of hair that start rotating when he gets fired up (moreso than usual, anyway).
 * Kicker's hair in Transformers: Energon goes white and ruffles whenever he predicts something.
 * Touka's Idiot Hair in Saki. It spins! It stiffens! It points every which way! It's like it has a life of its own!
 * Not exactly hair per se, but a hair piece. Tsukasa from Lucky Star's hair ribbon often straightens or goes limp and sagging, depending on her mood.
 * Misao's braid in Rurouni Kenshin often acts like a cat's tail: from stiffening (or getting a kink) when she's angry to curving up when she's surprised.
 * Chou, he of perpetually vertical Anime Hair, once claimed that he was so mad his hair stood on end. Kenshin snarked right back that Chou's hair is always like a broom.
 * Then there's Nono's hair, in Diebuster. It was part cute, part Crowning Moment of Awesome
 * In Bakemonogatari, Koyomi Araragi's hair this way and also serves on occasion to point out that Something Else Also Rises.
 * Ai Kaga has a ponytail that wags like a nervous dog's tail whenever she apologizes. Which is all the friggin' time.
 * Sernia Iori Flameheart of Ladies versus Butlers! presents us a particularly bizarre version of this trope: Her coiffure is already as ridiculous as it gets, with her curly pigtails which resemble two gigantic drills. If Sernia gets upset, those drills actually start spinning (complete with appropriate sound effects)!
 * On Keroro Gunsou, Momoka's Fawcett curls become sharp and pointy when her Split Personality takes over.
 * In the Railgun manga one page Mikoto's hair stands up waves around like an antenna points towards Touma, who is completely behind her at this point walking a different direction, and she runs after him. She has Touma seeking radar hair.
 * In Death Note, Light is noted for his ridiculously neat hair -- except at the very end, when it flies around like crazy.
 * In fact, any time he has a major freakout, his hair goes wild -- such as right at the start, and after L introduces himself.
 * Shugo Chara has Hoshina and her Expressive Pigtails.
 * In Aoi Hana, Akira's braids jump up whenever she is startled. Which happens quite a bit.
 * The titular character of Shinryaku Ika Musume has this in spades. Justified because she's a squid girl and the hair isn't hair, but ten very long, very fast, very powerful tentacles.
 * Yotsubato: Yotsuba's quadruple pigtails point downwards when she's sad and become rigid when she's exhilarated or shocked.
 * Although not used as extensively as many of the examples here, in IGPX Immortal Grand Prix major emotional shifts will cause Takeshi's hair curl to either point up for happiness or fall down for depression, complete with a corresponding slide whistle.
 * May from Pokémon did this a couple times during her first appearance in the anime.
 * Wandering Son, the manga version, is made of this trope. All the characters hair is expressive, and changes depending on their reaction or the general scene. Sometimes its just messy because it is, and other times they're shocked or surprised and it stands up.

Comic Books

 * In the Israeli comic Zbeng!, the female lead's hair colour changes based on her emotional state -- black when in mourning, red when angry, etc.
 * Franco-Belgian comics example: Titeuf.

Film

 * In Interview With the Vampire, Claudia's hair becomes curled and doll-like when she is turned into a vampire. Thereafter, whenever she tries to trim it, it grows back the same way.
 * Moe Howard of the The Three Stooges. Whenever he gets scared, his sugar-bowl haircut would fly up in a hilarious manner.
 * Ur Example? If A Body Meets A Body.
 * A sort-of example: Twi'leks don't have hair but rather 'head tails' where hair would be. They use those to communicate things only other members of their species can understand.

Literature

 * In A Tale of Two Cities, of all things. For most of the story, Jerry Cruncher's hair is simple described as very spiky, but in chapter thirty eight, while Jerry is being lied to, there is a "sudden extraordinary rising and stiffening of all the risen and stiff hair on Mr. Cruncher's head." As if to hammer the point home, Dickens relayed this to the reader by having another character notice the shadow of the hair moving on the wall.
 * Western Example: Pippi Longstocking.
 * Sumi in Moetan (pictured above) has various symbols appear at the end of her ahoge, including exclamation marks and Cross Popping Veins.
 * Susan Sto Helit in the Discworld novels has hair that restyles itself to fit the situation. It's assumed this is one of the powers she inherited from her grandfather, although it's obviously not one he uses himself.
 * Speaking of unfair unlives, it becomes a plot point that whenever Claudia in Interview With the Vampire tries to cut her hair, it grows back to the way it was, curled and doll-like, reminding her of her status as an eternal child. Interestingly, the movie shows her hair actually curling itself about her face as she gets vampirized.
 * In Warbreaker, one nation's royalty is able to change their hair color and length. Unless they are otherwise suppressing it, the color changes according to their emotions at the time.

Live Action Television

 * In Doctor Who, the Tenth Doctor has hair that sticks up a bit more whenever he's excited about something. It's not very noticable, but it's deliberate.

Theatre
"Macbeth: If good, why do I yield to that suggestion
 * Older Than Steam, apparently, if these lines from Macbeth are anything to go by:

Whose horrid image doth unfix my hair

And make my seated heart knock at my ribs

Against the use of nature?"

Newspaper Comics

 * In Dilbert, this is a qualification for becoming an engineer.
 * In Zits, Jeremy has a great poker face but terrible 'poker hair'.
 * In Peanuts, Linus' hair stands on end when he's startled.

Video Games

 * Daryan Crescend from Apollo Justice: Ace Attorney. He has a massive phallic-shaped hairdo.
 * It's supposed to be reminiscent of a shark, actually. Like everything else about him. Unfortunately, the entire fandom's mind is in the gutter, so...
 * Trials & Tribulations has Ron DeLite, whose cinnamon-bun curls of hair on the sides of his head uncurl and spring out when he's upset. This trope is actually pretty common across a lot of animations in the series, especially when the character is nervous.
 * Don't forget Pearls. The pretzel-hair mysteriously bounces when she's shocked, or grinning manically/happily. Also, when she's sad, her hair droops backward while she tilts forward.
 * Hell, Phoenix and Apollo themselves. Their hair looks quite downcast when they're losing, and returns triumphant come victory time.
 * Laharl from Disgaea has two hair "antennae" on his head that have the tendency to go stiff (or straight up) when he's particularly angry or annoyed.
 * Nikki's Idiot Hair from Mana Khemia Alchemists of Al Revis can get as angry as she is, which is often...
 * It may be the wrong category, but some fan depictions of Miki make her ahoge change shape according to her emotions.
 * Chrono Trigger: Kino's ponytail droops in his sad sprite. And it is absolutely ADORABLE.
 * Don't forget Marle, whose ponytail turns into a fro when she's startled.
 * Genki Girl Momoko from Aoi Shiro has short braids that stick up and go spiky when she is surprised or excited and droop when she's feeling down (not that that state of affairs ever lasts long).
 * Toyosatomimi no Miko of Touhou Project is occasionally portrayed as having this in fanon with her hair...flappies.

Web Animation

 * Mr. Milk from Making Fiends is almost completely bald, but has a few hairs on his head that stick up when he's scared or nervous. Charlotte seems to have an expressive bow.
 * Snake in Metal Gear Awesome does this a lot with his eyebrows. They become thicker, bushier and/or longer the more pissed off he gets. At one point, they grow to the point they resemble tree branches, complete with oranges sprouting out of them.

Web Comics

 * Multiple characters from Monsterful, Lawrence Spectrum flame hair is very expressive and often shows emoticons related to his emotions, including exciment or disappointment.
 * Samantha Thing also uses her hair to enhance multiple expressions like doubt.
 * Sapphire Gem hair shows this in a lesser degree.
 * Susan of El Goonish Shive: Dan says "Badass Hair in the Wind Effect With No Wind is your friend."
 * Not to mention Grace. Justified in that she actually has antennae from her uryuom blood.
 * The sorceress Suspiria in Flipside has her hair enchanted to reflect her emotions. It also becomes large and billowy when she does magic.
 * Freefall's Sam and Helix have expressive radio antennae.
 * From Gunnerkrigg Court, Antimony's fake antennae when she infiltrates the robot basement using a clever disguise.
 * In The KA Mics Gertrude's pigtails & Nikki's ponytail sometimes do this.
 * Yuki from Megatokyo, thanks to magic.
 * Misfile's Missi has had her pigtails stick out a couple times.
 * The author of Other Peoples Business has joked that Mercedes' hair is sentient, and attempts to restrain it will only incur its wrath.
 * In Sequential Art, Pip's strand/feather perks or droops depending on his mood.
 * Many fans consider this to be one of the most endearing things about Shadowgirls' resident Badass Normal Lindsey Jun Yeoh.
 * The girls of Wapsi Square have hair that behaves according to their moods. If happy, their hair is perky. It droops if they're sad, and it gets spiky and pointy if they're angry.
 * (Fallapart)Fernando the zombie from Unlife Is Unfair has some rather expressive antenna hair.
 * Blip: On this page, Angela wonders how K's hair does that; which is funny since Angela's hair can be just as expressive.
 * Used, and then lampshaded, in Questionable Content here.

Web Original

 * While never seen in action, the author of the web fiction serial Dimension Heroes has stated that the tufts of hair on Tami's head change depending on her emotions; when she's sad, they droop. When she's scared, they stick straight up. When she's furiously angry, they frizz out like a cat.
 * In Gaia Online's Valentine's Day '09 NPC Valentines, Blaze's gigantic ponytail is formed heart shapes.
 * A rare, real-life example: John of the Vlog Brothers has a nervous habit of running his hands through his hair when anxious, which causes it to get puffy.
 * Slipknot, a member of the superheroic Euroguard from the Global Guardians PBEM Universe, has long, superhumanly strong hair he can use as a set of hands. Naturally, it also reflects his emotional state.

Western Animation

 * The animated version of How the Grinch Stole Christmas.
 * Harley Quinn from Batman the Animated Series has blondepigtails when not in costume that perk up or droop, depending on her moods.
 * They still do it in costume, they're just stuffed in her hat and take it with them.
 * Sari Sumdac in Transformers Animated has the "sticking up pigtails" version, though it a couple occasions they friz up like a scared cat's tail.
 * Somewhat justified.
 * Parodied on The Simpsons. When Willie Nelson successfully reunites the family, his trademark braids rise like those of Pippi Longstocking.
 * Krusty the Clown on The Simpsons has expressive hair, especially on the season four episode "Lisa's First Word". During a Krusty Burger commercial for the 1984 Olympics, Krusty bites into a Krusty Burger. When the commercial ends and the director yells, "Cut!", Krusty spits out the burger and his hair droops (then slightly comes back up after he drinks some booze from a flask to wash the taste out of his mouh).
 * In some early episodes of Ka Blam!, June's ponytail seemed to stick up when she was scared or shocked, and drooped down when she was sad or tired. This was dropped after a few episodes however.
 * Loopy's pigtails seem to rise a bit when she's scared, curious or inspired.
 * Also in the episode "Comics of Champions", when June keeps on teasing Henry about his crush on Thundergirl, he gets so upset that his hair goes on fire, but June puts it out (wearing a firefighter hat with a siren in the background).
 * The Tick's antennae react in a similar fashion.
 * Pinkie Pie's hair in My Little Pony Friendship Is Magic, which is apparently made curly by sheer exuberance; when she's bummed out (as seen in "Cutie Mark Chronicles" and "Party of One"), it becomes straight.
 * In at least two episodes of Hanna-Barbera's version of The Little Rascals, when Darla is frightened, her hair resembles a brown sea urchin.

Real Life

 * This is actually Truth in Television, as humans still retain tiny muscles in the hair follicles that are used to puff the hair in most warmblooded animals, and this is the same reaction that give us goosebumps. Said muscles are much too weak to control long and heavy hair, but if a person has, say, a crewcut, it can visibly swell when that person is angry, afraid or simply cold.
 * Why do you think cats ripple when they're alarmed?
 * Part of this is a vestigial defense mechanism from when humans were much hairier animals. By making all the hair follicles on our body stand on end when we're afraid, we look larger to predators and have a chance of scaring them off.
 * Some birds (like cockatoos and bluejays) have expressive feathers on their heads (crests).