The tongue pushed deeper and your vision went blurry—eyes crossing at the sensation it wrought upon the nerves in your rear. A shiver ran through you as your everything became overstimulated. If you weren't already collapsed on your chest—rump in the air—you would have fallen down.

The tongue was fantastic in and of itself. Each stripe on the rubbery surface was a ridge that played a note upon your sphincter each time it pushed in deeper—and that's all it seemed to do. Deeper and deeper. You shouldn't have any room left, but it kept going.

Wetness seemed to start leaking over your rump. Barely able to see let alone move, you flopped your head to the side and watched the pink, rubbery stuff flowing over your hips—sculpting them into a mirror of the rubber pony's.

It's making me into a copy of itself, you thought as more of your back end was covered. Your legs reshaping under the glossy rubber—merging with it and becoming rubber themselves. It was very quickly too much—a climax ripped through you as the rubber progressed.

Deeper that tongue went, and with every inch it moved inside you it converted you. Soon your body was rubber (and pony) from your chest down—or up as the case may be. A squirming feeling in your throat didn't surprise you, and when the tongue pushed out of your mouth, so too did a rush of pink slime. It poured back over your face, stealing your sight completely until it stretched thin enough that you could see through it.

The tongue moved, squirmed, and then you realized it was you moving it. Your brain—now rubber itself—played catch-up with the transformation as pink rubbery ears pushed from the top of your head. You watched the rubber build up between your eyes into a snout.

"M-Me?" you manage to ask.

"Yes. Both of me," the mare answered as she walked into view.

New connections in your head guided your rubbery legs into a standing position—on all fours.

Author's Note

Made after seeing this lovely creature on Discord.

Support me on Patreon or fuel my writing on Ko-Fi!

Join me on Discord. Warning, said chat may contain NSFW material and should be considered adult in nature.

Awesome ponies who are already helping to keep me in keyboards and rum:
A.P.O.N.I.
Canary in the Coal Mine
Daremo
Dio-Drogynous
Ender Voidwalker
KFS Crimson
Sirion123
Vi Watch
Wind of the Skies

And special thanks to the following, for careful eyes and friendly words:
Lab