Mean Six

The Mean Six are the secondary-turned-main antogonists of the MLP: FiM episode of the same name. They are clones of the Mane Six created by Queen Chrysalis, but they end up turning against her.

History
The episode begins with Chrysalis posing as a photographer taking pictures of Princess Twilight and her friends and taking strands of their hair in her latest plot: to create dopplegangers of them that would obey her and have them utilize the Elements of Harmony to conquer Equestria and get revenge on Starlight Glimmer.

To be continued...

Appearance and Personality
As copies of the main characters, their appearance is almost completely identical, except their colors are dimmer, their manes are messier, Applejack's cutie-mark show green apples instead of red, and Twilight's eyes are more red.

Despite being clones of the Mane Six, their personalities are completely opposite of the originals: Fluttershy is a sadistic bully and animal abuser, Pinkie Pie is a grump and pessimist, Rarity is a greed-crazed hoarder, Applejack is a compulsive liar, Rainbow Dash is a faithless loafer, and Twilight Sparkle is a would-be tyrant who constantly criticizes others. Also, none of them have any qualms of betraying Chrysalis for thir own gain.

Trivia

 * The Mean Six are identical to the Mane Six when they were under Discord's spell.
 * They are the only villains in the series whose existence was never known to the heroes.