Image imported from derpibooru 
Original Description:
 
Changing form isn’t pretty. It makes it more evident when it’s about changing into the queen of the changelings, Queen Chrysalis. It can be quite grotesque in fact.
 
Your skin hardens into chitin and your back is being covered by a solid green carapace. All of your flesh is moving and shifting within you. You’re feeling the growth of your hair on top your head, now a long flowing cerulean mane. Your new tail is also growing out behind you. You’re being forced into a quadruped position like a pony. Speaking of ponies, your face pushes out to form a muzzle, your hands and feet disappear in hooves and your ears become long and pointy. Wings sprouting out of your back, they’re transparent and with lots of holes but can still surprisingly lift you up in the air. A tall crooked horn grows proudly on your forehead, enabling you to do changeling magic. Finally, all the female touch happening all throughout it, of course.
 
Chrysalis was made to be scary and intimidating, yet still be the matriarch for all of the changelings.
 
In the mean time, you’re being magically transported to Queen Chrysalis’ royal throne ro-… or rather Princess Cadance’s bedroom? Uh oh, in that case, you’d better learn to be a real changeling fast. Take Cadance’s form and imitate her just enough to evade any suspicion. Your wedding ceremony with Shining Armor is coming soon. Oh, and try to keep him still under your spell of course.
 
More importantly too, just try to watch out for Shining Armor’s visiting sister. That purple unicorn will be more of a challenge to convince. And if you’re good enough, she’ll be you little stepsister soon…