(source)

Before Maud could react, the not-rock pulled itself up and over her hoof. She jerked back, but not fast enough. The goopy not-rock slid further up her limb, leaving a perfect, granite-like rubber surface behind.

Staring at her hoof, Maud didn't notice the not-rock crawling higher and reaching her shoulder. She lifted her foreleg up and examined it. What came to mind was when her coltfriend had been petrified, and while it was a little harder to move with the encasing rubber, the look of it more than made up for it.

As the not-rock spread out from her torso—down, up, and along her other foreleg—Maud quickly realized its full intentions. Despite the certain knowledge it would encase her, her granite-colored, encased hoof reached down and under her. "Mmmm...." The guttural sound slipped from her mouth as she realized the texture of her hoof was just like rock. She probed deeper as her torso was engulfed in matte-gray rubber-stone. When the not-rock coating reached the underside of her jaw, Maud's hear quickened, and she she shoved her whole hoof into her cleft.

The resultant moan was stifled as the granite-colored rubber reached around her snout and with inexorable pressure forced it closed. For a moment Maud was fearful she couldn't breathe, but to her delight she found it was porous. The not-rock reached her tail and compact udder, circling the former and squeezing at the latter. Maud was increasingly trapped in a fortress of rubber-stone, and she'd never been as horny in her life.

When the not-rock passed over her tailhole and the last of her udder, there was just a short distance for it to cover before she'd be trapped within its cold embrace, but that path was blocked by her hoof. The rubbery stone melded against her limb—which was still covered—and Slowly its surface tension forced the hoof from her body.

Maud whimpered, not just for the loss of stimulation, but because the not-rock was flowing over her eyes. The word turned dark, and she had her last view of granite-colored rubber as it sealed her sight away.

The rest of the mare disappeared quickly under the strange material—her back legs, the top of her head, and finally her mane and tail were encased as well. Sitting still, Maud knew that she shouldn't be enjoying becoming one with a rock so much, but she did anyway. She slowly shifted her weight, pushed her legs under herself, and stood up—just as the not-rock formed up intrusions at her mouth, ears, ass, and vulva. Maud's eyes widened in their dark prison as her body was invaded by the not-rock. Her mouth was forced to stretch around a swelling stone-textured shaft, as was her vagina and anus. The sounds of the world around her were driven out of her perception as the tiny plugs sealed up her ears.

Maud stood in absolute bliss—still as a stone—as she was made complete.

———

Mud Briar smiled at his fillyfriend—encased in her own little prison. "I hope you like it. It's a one-of-a-kind, and the best I could find."

Maud didn't hear him, she couldn't, but that didn't stop her from trembling through another of the best orgasms of her life.

Author's Note

To find, ~~head to derpibooru and use the number 2097252 after the url. (or search for~~ ID:2097252~~)~~ https://derpibooru.org/2097252

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