"Danger's my middle name. Rainbow 'Danger' Dash."
"Ten. Seconds. Flat."
- Rainbow Dash
Rainbow Dash is a light blue Pegasus pony with rainbow colored hair. She is a Flight School drop-out and spends her days controlling the weather and practicing her flight skills. Her biggest dream is to join the Wonderbolts, a highly skilled team of Pegasi who perform shows all around Equestria. She is athletic and extremely competitive. She is the first and only pony to achieve the Sonic Rainboom, which won her first place in the Best Young Flyer competition held in Cloudsdale. Pulling off the Sonic Rainboom also earned her a cutie mark when she was a filly. Her cutie mark is a multi-colored lightning bolt shooting out of a cloud; it represents her althetic achievements. She represents the Element of Loyalty. She has a pet turtle named Tank.
How Rainbow Dash & Thomas' Friendship Began[]
When Rainbow Dash and her friends, the Mane Six, first arrived to the Island of Sodor, she happens to work with Gordon the Big Express Engine. She was also very cocky, arrogant and rude to the other engines and thought none of them were as really useful and grand as Gordon. Thomas always thought she was being too big for her hooves, and his friends had to agree with him, especially Gordon, who couldn't stand Rainbow's bad behavior either.
One day, Rainbow was boasting as usual to Thomas that he should get wings on his side tanks and be more up-to-date, but he refuses and remarks to Rainbow Dash that she looks like an odd bluebird and even comments that she doesn't go much faster and doesn't help out any of the engines. Rainbow takes offense and was about to retort until Thomas bluntly interrupts her about being the fastest Pegasus in the world and referes about her eating her boastful words when she was beaten by a "certain old tram engine" in a race at Ghastly Gorge. The blue Pegasus feels insulted and gloats that she is still the fastest and can handle any job ten seconds flat. But when Thomas comments about her sleeping ten times for three days, she seethes with rage and furiously calls Thomas a "stick-in-the-mud", which made Thomas livid.
Thomas and Rainbow Dash having a brutal argument.
For days, Rainbow kept calling Thomas more rude names and they kept arguing. It gotten so bad that they each ended up back to back. Twilight Sparkle and Edward were worried about Thomas and Rainbow Dash's rivalry, so they each try to comfort them and sooth their anger; Twilight explains to Thomas that Rainbow doesn't mean any harm, but he still feels offended by Rainbow's name calling. At a different location, Edward explains to Rainbow Dash that he knows about Thomas for many years and says that he has a similarity with her. Then he advises that they will be very good friends once they start working together and getting along. But the cocky Pegasus refuses to take the advice and says to Edward that he is an old pile of scrap that talks nothing but nonsense. The old engine then warns her that one day, her bad attitude would come back and haunt her. One rainy morning, Rainbow Dash was ordered to work with Stepney to deliver workmen; she was very annoyed by it and flies away, grumbling. A little later, when Thomas was warming up, the guard arrived in an empty truck and told them there was a landslide (big rocks and mud mixed) outside of the tunnel and Rainbow Dash was stuck in it. Thomas refused to help at first, but when his fireman reminded him of Stepney and the workmen, he quickly set off. He finds Stepney, who was in tact but unable to keep going. As Thomas asks the him where Rainbow is, they both hear sobbing. Thomas puffs forward to see Rainbow Dash with her wing caught under a heavy rock; she was crying because she was in pain. Thomas, who has never seen the blue Pegasus cry before, felt very bad for her, but pretends to not take any notice. The workmen first clear away the tracks to allow Stepney to carry on with his journey. Then Thomas freed Rainbow Dash and her wing from the heavy rock by using strong chains. Afterwards, when her wing is fully healed, Rainbow came to Ffarquhar Station to see Thomas. She apologized and thanked him for rescuing her, and they burst out laughing when they realized Rainbow Dash was the real stick-in-the-mud after all.
Edward and Twilight begin to worry while Rainbow Dash and Thomas are back to back, sulking.