Foster's Home for Imaginary Friends/My Little Pony

Jennifer Parker (from Back to the Future) as Twilight Sparkle

Mac as Spike

Frankie Foster as Rarity

Audrey (from The Lorax) as Rainbow Dash

Wendy Corduroy (from Gravity Falls) as Applejack

Candace (from Phineas & Ferb) as Fluttershy

Mabel Pines (from Gravity Falls) as Pinkie Pie

Marty McFly (from Back to the Future) as Flash Sentry

Duchess as Nightmare Moon

Terrence as King Sombra

Gwen (from Sky High) as Queen Chrysalis

Biff Tannen (from Back to the Future) as Lord Tirek