Sweetie Belle cast a spell that made the Cutie Mark Crusaders into full grown mares.They still don't their cutie marks or any maturity whatsoever.
Original concept: Pencil Lead/Bubble Berry
Chapters 1-2: Pencil Lead/Bubble Berry, 3-6: MintGreenConspiracy
Edited by: 3-5: Pencil Lead/Bubble Berry, 4-5: m2pt5/Emtu, 6: LavendarRegards
Cover art suggestion: MerlosTheMad