The Cutie Mark Crusaders

The Cutie Mark Crusaders are a group of three young fillies (Apple Bloom, Sweetie Belle, and Scootaloo) who have yet to earn their Cutie Marks, marks on a pony's flank that represents the talent or ability that makes them unique. Because of the bullying they received for not yet having Cutie Marks, such as being referred to as "Blank Flanks," they banded together to help one another earn their Cutie Marks. This leads them into antics and misadventures as they try out various harebrained schemes to see if they can achieve their goal. This is not successful, but their special talents sometimes become apparent.

While visiting Ponyville, Apple Bloom's cousin Babs Seed joins the Crusaders because she too has no Cutie Mark yet and is tired of being bullied for it. As she leaves for the return trip to her home in Manehattan, she promises to start up a branch of the club there.

Apple Bloom
Applejack's younger sister, Apple Bloom (voiced by Michelle Creber) is a yellow earth pony with a red mane and tail, red/orange eyes and wears a pink bow on her head. She has a strong Southern American accent like Applejack, but it fades when she talks to someone she does not like, or whose approval she seeks. Together with Scootaloo and Sweetie Belle, she forms the Cutie Mark Crusaders, and is in some way presented as the leader of the group. In "The Show Stoppers", Apple Bloom appears to know martial arts and is skilled at design and carpentry, as she quickly renovates Applejack's old tree house for the Crusaders' use.[19] She also appears to be the most level-headed of the Crusaders, typically acting as the voice of reason.

Scootaloo
Scootaloo (voiced by Madeleine Peters) is an orange pegasus pony with purple eyes and a purple mane and tail. She usually sees Rainbow Dash as a sister. Scootaloo is a tomboy like Rainbow Dash; she is adventurous, brave, and opinionated. Even though she can't exactly fly, she uses her tiny wings to give her extra propulsion when riding a scooter and to help her perform stunts. She can also hover for short periods. She idolizes Rainbow Dash, and is the president of "The Rainbow Dash Fan Club." In The Show Stoppers, she has a a big talent for activities that require agility, such as stunt driving, dancing, and choreography, though she is oblivious that this may be her special talent. In Sleepless In Ponyville, Scootaloo tries to put on a tough-pony facade for Rainbow Dash during a camping trip, but is in fact terrified of the fearless Rainbow's scary stories. When she finally breaks down emotionally and admits her fear, Rainbow reveals that she too was scared when she first heard those stories as a filly, and the pair form a close sister-like bond as she takes Scootaloo under her wing to teach her how to be fearless.

Sweetie Belle
Rarity's younger sister, Sweetie Belle (voiced by Claire Corlett) is a white unicorn pony with a pink and purple mane and tail and light green eyes. Sweetie Belle tends to be a slower thinker than Apple Bloom and Scootaloo, but is as excitable as them and will readily follow their lead. Though she wants to be a designer like Rarity, her inexperience and clumsiness prove to be a hindrance when she tries to assist in the shop, and when she designs set pieces for a talent show. In The Show Stoppers, she has a talent for singing and songwriting. She turns one of Fluttershy's lullabies into a rousing gospel number in Stare Master, but prefers not to sing in public. She has not yet demonstrated any ability with her horn beyond a few light sparks when she gets excited, and her attempts at cooking lead to disastrous results such as burned fruit juice and charred, liquefied toast.

Source: http://en.wikipedia.org/wiki/List_of_My_Little_Pony:_Friendship_Is_Magic_characters