"Rainbow Dash, who could not abandon her friends for her own heart's desire, represents the spirit of loyalty!" — Twilight Sparkle
Rainbow Dash first appears in Friendship is Magic, part 1, where she accidentally crashes into Twilight Sparkle, knocking her into a mud puddle. During their ensuing exchange they get to know each other for the first time. Rainbow Dash later joins Twilight and four other ponies in Friendship is Magic, part 2 on their quest for the Elements of Harmony. Halfway into the journey, Nightmare Moon attempts to stop them by taking the form of the Shadowbolts, an imitation of Rainbow's favorite aerobatics team and using them to deceive Rainbow into abandoning her friends. However, they fail as she declines their offers of fame and power to help her friends and continue the quest. It was by this act she earned herself control over the element of loyalty. Rainbow Dash's loyalty is put to the test in The Return of Harmony Part 1 and Part 2. She and her friends must solve Discord's riddle and play by his rules to regain the Elements. During their mission, Rainbow Dash falls victim to Discord's manipulation after he tells her that her home will crumble without her, and shows her an illusion of Cloudsdale falling. Under Discord's influence, she abandons her friends (using her wings that he gave back to her) to "save" a cloud she believes to be Cloudsdale. Right before Applejack spots Rainbow Dash flying away, Twilight Sparkle reassures herself by saying Rainbow Dash won't let them down, but then watches in disbelief as Rainbow Dash speeds off. Discord reveals himself and informs the other ponies that they have been disqualified, as one of his rules stated that if any of the ponies use magic or their wings, the game is over. The following episode, when Twilight sets about finding her friends to undo what Discord had done to them with a "memory spell", Rainbow Dash dismisses Twilight's plight with "loyalty shmoyalty". Since she won't come close enough to Twilight for the spell to be performed, the ponies must combine their efforts to catch her and bring her to the ground. Her first words after her corruption is undone is "How's Ponyville? Where are the Elements? Did we stop Discord?" With Dash by their side again, the ponies wield the Elements of Harmony and defeat Discord with their magic.
Brashness and apparent laziness
Rainbow Dash is very confident in her abilities, which is often construed by others as laziness. When Twilight Sparkle first meets Rainbow Dash, she has none of her cloud cleanup work done, and lies idly on a cloud, putting off her work. Despite her apparent laziness, she performed her duty in "ten seconds flat", leaving Twilight wide-eyed at the sight. She languishes about in Griffon the Brush Off, The Cutie Pox, and Swarm of the Century, but springs into action in the last second when she's needed to help deal with the parasprite infestation, and leaves off for duty when she's needed in the first. She is the leader of the weather team in Winter Wrap Up and she volunteers to go on important missions with her friends, so despite her apparent laziness she is a hard-working, contributing pony. Rainbow Dash proudly says in Boast Busters that she's better than the rest of the ponies, but boos Trixie when Applejack gives her a scornful look. She and Applejack deride Twilight Sparkle in Fall Weather Friends for being an "egghead" and not having any experience with running outside of what she read in her book. However, both of them admire her magic in Boast Busters and tell her they're proud of her. Rainbow Dash doesn't hide her annoyance at her friends' behavior, mostly with Fluttershy throughout season one. On the ponies' expedition in Dragonshy, Rainbow Dash is annoyed with Fluttershy's cowardliness throughout their journey, in Suited for Success she angrily scolds her for suggesting panic, and in Sonic Rainboom she becomes so frustrated with Fluttershy's meek cheering that she does a pratfall. It is worth noting that despite her rude attitude towards Fluttershy, she doesn't apologize to her in the long run.
In Hurricane Fluttershy, she is shown to have a great amount of patience and compassion for her friends. While Rainbow Dash remains supportive and encourages her to help, Fluttershy cannot overcome her fear of being humiliated for her lack of wing power. At the end, when Fluttershy succeeds in helping funnel the rain water to Cloudsdale, but accidentally keeps on flying round and round, Rainbow Dash expresses her gratitude with an overjoyed hug and proudly calls Fluttershy a champion flier. She begrudgingly lets Rarity give her a makeover in Swarm of the Century, and keeps an annoyed frown on her face in the process. When Twilight Sparkle tries to convince Rarity in Suited For Success that she's not a laughing stock, Rainbow Dash rudely quips "she kind-of is". Like the other ponies' dresses, the dress she asked Rarity to make her is over the top, and it even includes a helmet styled much like the one worn by The Rocketeer. However, she wears the dress Rarity originally designed for her with a smile on her face when Rarity is given a chance to redeem herself. She calls a dragon lame after seeing one do a trick, but then gets her coat singed after nearly getting burnt by another dragon's fire breath. She also mocks Spike in the same episode, but is then scolded by Rarity.
Competitiveness and athleticism
Rainbow Dash describes her passion for winning in a flashback in The Cutie Mark Chronicles. She races several times with Gilda, her old friend from Junior Speedster flight camp, in Griffon the Brush Off, and challenges Applejack in a series of athletic competitions in Fall Weather Friends. Despite Rainbow Dash's competitiveness and confidence, she reacts poorly to failure, or even the possibility of failure. She gets upset over losing a simple game of horseshoes to Applejack, saying that she "hates losing". During the Iron Pony competition, she uses her wings to give herself an advantage, which Applejack considers cheating. Even though Rainbow Dash's wings are tied down for the Running of the Leaves to keep it fair, Dash continues to use underhanded tactics. Applejack, fed up with what she considers to be foul play, returns it in kind. Both end up tying for last place, and they apologize to each other and Princess Celestia before running the race again in good spirits. In Sonic Rainboom, Rainbow Dash initially displays overwhelming bravado about her impending performance in the Best Young Flyer competition. However, when Rarity starts showing off her magical butterfly wings and attracts a lot of attention and admiration, Rainbow Dash quickly loses confidence. She nearly refuses to participate in the competition, and she makes mistakes in the first two parts of her flying routine. However, she successfully pulls off the sonic rainboom and earns the title of "Best Young Flier" when she flies fast enough to save Rarity and The Wonderbolts.
In May the Best Pet Win!, Rainbow Dash puts her prospective pets through tests of speed, agility, style, guts, "coolness", "awesomeness", and "radicalness", the qualities that she values most in a pet. The tie-breaking contest for the remaining candidates is a race against Rainbow Dash herself.
Rainbow Dash tries to spook her friends when they venture into the Everfree Forest for the first time, claiming that no pony has ever made it back out of the forest. Her reputation as a prankster is established in Griffon the Brush Off, where she and Pinkie Pie prank various ponies, and is further enforced in A Bird in the Hoof, when she tries to make the royal guards laugh. Rainbow Dash plays several pranks on her friend Gilda in Griffon the Brush Off, which were set up for Gilda's party, but are not specifically aimed at her. For the majority of the time when Gilda is visiting Ponyville, Rainbow Dash is unaware that the griffon is being callous and rude to the other ponies, but the pranks at the party get the best of Gilda, and she loses her temper in front of Rainbow Dash. After witnessing this side of her personality, she calls her out on her behavior and sends her on her way. Dash uses a cloud to create thunder and lightning to scare Spike in Griffon the Brush Off, as a prank. She does the same to Pinkie Pie and various other ponies in Luna Eclipsed while dressed as a Shadowbolt, laughing at the ponies she frightens. She tells Twilight Sparkle that "this is the best night of the year for pranks" and that "it's all in good fun". She then hurries off to scare another group of ponies, which she continues doing until Princess Luna decides to declare payback for all of the trouble she'd caused that night. She also displays this in It's About Time, taking advantage of Twilight's worrying to spook her, along with Spike.
Love of reading
Rainbow Dash discovers she loves reading in the episode Read It and Weep. When Twilight first offers her a book to read through her stay at the hospital, she rejects it and testily tosses away the book, saying "I'm a world-class athlete; reading's for eggheads like you, Twilight." After a short boredom montage, she picks up the book and discovers she loves reading, much to her chagrin. She spends much of the episode trying to hide the fact that she loves reading from her friends, and when she's discharged from the hospital she tries to get re-admitted so she could finish reading the book. The doctor recognizes that she's only feigning being ill and accuses her of laziness. She then sneaks back inside the hospital and attempts to steal the book, but gets caught red-handed and drops it while making her escape. She is pursued and eventually caught, and she admits she was after the book and that she loves reading. Twilight Sparkle has a personal copy of the book she was reading in the hospital, and lends it to Rainbow. The episode concludes with her finishing the book and excitedly picking up another one from a small stack, entitled 'Daring Do and the Griffin's Goblet'. She can also be seen reading more Daring Do books in A Friend in Deed and Too Many Pinkie Pies. In Spike at Your Service, she mentions that she's writing a novel, one which is about "this awesome Pegasus who's the best flyer ever, and becomes the captain of the Wonderbolts"; Rarity comments sarcastically about the complexity of its plot.
Rainbow Dash wears a pair of black-tinted glasses several times in the show: in Lesson Zero when Dash and her friends gather for a picnic; in May the Best Pet Win! when Dash states that her pet must have substantial "radicalness" and when she is questioned by Twilight Sparkle for not explaining the difference between "awesomeness", "coolness" and "radicalness"; in The Mysterious Mare Do Well when she is bragging about her heroic acts; and in Too Many Pinkie Pies, while sunning herself by the lake.
Flying and weather manipulation
Having demonstrated remarkable speed and agility in the air, Rainbow Dash has proven herself to be a capable and accomplished flier. She speaks of and demonstrates her impressive and spectacular aerial acrobatic maneuvers in The Ticket Master, which include: the "rainblow dry", which she uses to clean up Twilight Sparkle in the first episode; the "super speed strut"; the "fantastic filly flash"; and the "buccaneer blaze", which involve strutting while flying, a nose-dive and recovery that creates a flash, and the creation of multiple bolts of lightning, respectively. On one occasion she uses her flying skills and physical strength to help Applejack demolish a barn in Lesson Zero. She ruthlessly tears through the structure from all directions, and eventually dives into it from a great height, finishing it off in a savage yet vibrantly-colored explosion that sends debris raining down upon Applejack and Twilight.
She demonstrates her flight skills in May the Best Pet Win! to her potential pets: she zips straight up into the sky; flies to a far-away hill leaving a trail of rainbow-colored flames behind her; maneuvers in sharp 90-degree turns between the candidates while leaving a vertical rainbow-colored streak behind her; and swirls around a cloud to create a pony cloud sculpture. Near the end of the episode she performs numerous perilous stunts as part of her demonstration run through a treacherous race course that would decide the pet she would choose, the stunts including flying through giant bramble patches and dodging attacks from colossal quarray eels. Rainbow Dash has demonstrated her prowess with manipulating weather numerous times. She clears the skies of Ponyville of clouds "in ten seconds flat" in the first episode, dispersing the clouds by kicking them. She leads water droplets out of a cloud in Boast Busters, and creates a rainbow above her when the droplets splash against her. She teams up with other Pegasus ponies in Winter Wrap Up to create a whirlwind that sucks away clouds and snow from Ponyville, and she creates a tornado to vacuum the parasprites in Swarm of the Century. In Hurricane Fluttershy, Rainbow led the Ponyville Pegasi in creating a hurricane that would lift enough water to Cloudsdale for the rainy season. During this time, Rainbow's wing power was measured at 16.5, while most of the other Pegasi's wing power could barely measure more than 10.
Rainbow Dash performing her "sonic rainboom" Rainbow Dash's most venerated move is the sonic rainboom, first depicted in the aptly-titled episode Sonic Rainboom. This is the second time in her life that she has performed the trick, the first being depicted in a later episode, The Cutie Mark Chronicles, where it indirectly leads to each of the six main characters gaining her cutie mark. Even though several ponies are present to witness the sonic rainboom in Rainbow Dash's flashback, the very same ponies consider the maneuver a myth in Sonic Rainboom.
She was apparently unable to be able to pull off the maneuver intentionally until A Canterlot Wedding - Part 2, when she carries it out it as a show for Princess Cadance and Shining Armor's wedding. She does not show any hesitation when given her cue to commence the flyby and pulls it off with utmost ease and perfection. However, it was evident that the maneuver required a reasonable amount of practice to be able to carry out as well she did.
Equestria Games announcement
Rainbow Dash has a flashback in Games Ponies Play to an event in Cloudsdale where she is a young filly without a cutie mark. She is accompanied by a stallion who has similar rainbow-colored mane and tail as her and a similar blue coat, with a rainbow-colored cutie mark. They are standing in the crowd listening to an announcement about where the Equestria Games will take place. When Dash hears they won't take place in Cloudsdale, she cries out in disappointment.
Rainbow Dash mentions in Call of the Cutie that she was the first in her class to get her cutie mark. She tells the Cutie Mark Crusaders in The Cutie Mark Chronicles the story of how she got her cutie mark. Her story is set in summer flight camp, where she defends Fluttershy from a pair of bullies, who refer to Rainbow Dash as "Rainbow Crash", which she is also nicknamed by Spike in Bridle Gossip. One of the bullies already have their cutie mark, where Rainbow Dash and Fluttershy do not. She challenges the two bullies to a flying Pegasus race, and in the ensuing contest she discovers her passion for speed and for "winning", in her words. Going through the race course, she performs her very first sonic rainboom, not only gaining her own cutie mark, but also inadvertently setting in motion the events that would cause Fluttershy and her future Ponyville friends to gain their own cutie marks.
Rainbow Dash tries to perform a sonic rainboom in the episode Sonic Rainboom, in an effort to win the Best Young Fliers competition. Fluttershy confides to her friends that Rainbow Dash was unable to perform the move in her many practice trials. Nonetheless, Rainbow Dash heads to Cloudsdale to participate in the competition, accompanied by Fluttershy as moral support. Much to their surprise, their wingless friends have decided to follow them with the aid of Twilight's cloud-walking spell, easing Rainbow's fears. However, Twilight had also given Rarity beautiful wings, which led her to steal the spotlight. As a result, Rainbow Dash loses her nerve and tries to delay her performance. As the competition draws to a close, however, she decides that she must perform anyway. Dash messes up the first two rounds of her performance, hitting an obstacle and accidentally sends a cloud hurtling in the direction of Princess Celestia. Due to time constraints, Rarity performs alongside Rainbow Dash, and delivers her grand finale, which involves flying up to the sun and beaming her wings. However, her fragile wings, made of "gossamer and morning dew", burst into flames, sending her plummeting towards the Earth. The Wonderbolts try to save her, but Rarity kicks them by accident due to her falling down, and they are knocked out.
Rainbow Dash finally notices the goings-on and accelerates towards the plummeting ponies, saving both Rarity and the Wonderbolts and performing a sonic rainboom in the process. Both this sonic rainboom and the one in The Cutie Mark Chronicles are performed when Rainbow Dash is leading with both front legs forward, while in her failed practice attempts she is leading with a single leg. Rarity is incredibly grateful that Dash saved her life, and apologizes to her friend not minding her anxiety. Rainbow Dash is crowned the winner of the competition and leaves off to spend the day with her heroes, the Wonderbolts. In A Canterlot Wedding - Part 2, bolting her bridesmaid dress off, she performs a sonic rainboom for the marriage of Cadance and Shining Armor by the request of Princess Celestia. This rainboom, unlike the other two, comes faster and is performed while flying upward.
The Cutie Mark Crusaders
Despite earning her cutie mark in an endeavor that came naturally to her, Rainbow Dash advises Apple Bloom to try out many different activities to gain her cutie mark in Call of the Cutie, leading the filly and her friends to pursue their cutie marks in the wrong avenues. When coaching Apple Bloom in Call of the Cutie, Rainbow Dash dons a sports headband, a whistle, and later a martial arts uniform with a black belt when Apple Bloom tries karate. Scootaloo, the Pegasus pony of the Cutie Mark Crusaders, idolizes Rainbow Dash. While Apple Bloom and Sweetie Belle are the younger sisters of two ponies from the main cast, Applejack and Rarity, respectively, Scootaloo is not related to Rainbow Dash. Rainbow Dash affectionately calls Scootaloo "squirt" in Owl's Well That Ends Well and The Mysterious Mare Do Well, and appears alongside Rarity and Applejack to congratulate the Cutie Mark Crusaders for their performance during The Show Stoppers.
In Sleepless in Ponyville, Scootaloo invites Rainbow Dash on a camping trip so that they can bond more. However, when Rainbow Dash decides to tell everyone ghost stories, Scootaloo begins to have nightmares about the frightening fables; yet she is too afraid to tell Rainbow Dash, since the filly does not want her to think she's a wimp. When Scootaloo rides on her scooter in the middle of the night, trying to run away from the "Headless Horse" from one of the stories, she accidentally falls into the river and almost falls down a waterfall. Rainbow Dash rescues her, and then learns the truth about why Scootaloo has been acting nervous during the trip. She comforts Scootaloo, saying that even she was scared when she heard those stories, and she agrees to take care of her as a big sister figure.
Rainbow Dash manages the weather in Ponyville. She keeps the skies free of clouds for the Summer Sun Celebration, and apparently, unless the weekly rainfall is scheduled for that day of course, makes sure that Ponyville has nice weather, although in the opening of Bridle Gossip, Spike states that she rarely gets up early in the morning to get a start on it. She lives in a cloud-house near Ponyville, which has the same design elements as her hometown, Cloudsdale.
Rainbow Dash is one of several ponies badgering Twilight for the extra ticket to the Grand Galloping Gala, in The Ticket Master. Her reason is a chance to audition for The Wonderbolts who would presumably perform there. She persists, even when Twilight calls her out on it, and when all her other friends say they don't need the ticket. The Wonderbolts do appear at the Gala in The Best Night Ever, although their performance is not shown, and they are only seen mingling with the guests in a VIP section, but Dash doesn't manage to secure their attention, despite her several attempts. In The Mysterious Mare Do Well, she saves a dirty filly who thanks her for the rescue from the deserted well.
Rainbow Dash was accepted into the Wonderbolts Academy for a week. She made friendship with a pegasus pony called Lightning Dust, and were paired up by the captain of the Wonderbolts, Spitfire to complete the boot camp exercises. In the challenge of obliterate the clouds, Lighting Dust tried to complete the task quicker by creating a tornado. Unfortunately the tornado almost hurts Twilight Sparkle, Pinkie Pie, Rarity, Applejack and Fluttershy when they come to visit her in the hot air balloon. Rainbow Dash saves them just in time, injuring her wing in the process. She decided to quit the academy thinking they reward cadets for being reckless. But Spitfire catches up to her and informs her that being the best should never come at the expense of their fellow ponies. Being elite isn't about pushing oneself, it's about pushing oneself in the right direction, which Rainbow Dash has demonstrated. Because of this she was awarded the lead pony badge.
Rainbow Dash is the last of the main ponies to have a pet introduced in the series, only gaining her pet, Tank the tortoise, in the episode May the Best Pet Win! in the second season. While at first Dash looks down on Tank for not being as fast, agile, or "awesome" as her other prospective pets, she eventually picks him over the others for his loyalty. While all the other prospective pets hurried to the finish line and ignored Dash's calls for help, Tank rescues her by releasing her trapped wing from under a boulder. He carries her all the way to the finish line, and secures his place as her pet for being the only competitor that crossed the finish line with her, as she specified before the race.
In Games Ponies Play, during her flashback as a filly, Rainbow Dash is shown standing on the back of an adult Pegasus stallion with a similarly rainbow-colored mane and tail. Her relationship to the stallion is not explicitly referred to.
Rainbow Dash's home is first shown in Griffon the Brush Off. She lives in a white cloud-house hanging low to the ground somewhere near Ponyville. It features classical columns and rainbow-colored streams and waterfalls. In Dragonshy, Rainbow Dash uses one of these streams to make rainbow-colored facepaint. Her home is shown again in Party of One, with a slightly different design from the first appearance, resembling more of a cloud tower. The interior is shown in Swarm of the Century, and her bedroom is shown at the end of Read It and Weep. The exterior is shown again at the beginning of Wonderbolts Academy, along with her mailbox underneath it.