you tripping around ponyville while rainbow Dash is doing her usual fly, do her rainboom, do it always, but now something went wrong that turned all the stallion in colt and all the mares in fillies...

Rainbow Dash: flying and finishes Oh ye- WHAT WHY I TINY!??

Twilight: horn glowing but don't works right MWY MAGIC!

Rarity: WHY IM SO LITTWE!? I CAN'T DO MY DWESSES NOW!

Applejack: bucking apples until it hurts by my little hoofes and my hat falls by un-enough size OWWCHH THAT'S INFAIR!!

Pinkie Pie: YAYAYAYAY!! PARTIES AND PARTY- notices my little body WOAH!

Fluttershy: talking with my animals until notice they're puppies and I filly again WUH... WHAT!??