As Jon slept, he began to change. Tawny fur began to creep across his body, running up and down the length of his torso and all along his limbs, leaving only his neck and head uncovered. His neck grew slightly longer as his body changed shape, his torso becoming longer and deeper, more of a barrel shape, as his limbs became shorter and stockier, his fingers shortening as his hands and feet alike reshaped into broad paws, the tips of their toes sprouting large claws.
The muscles in his back legs became large and powerful, making his haunches prominent and tearing at the seams of his pajama shorts as he pulled them up against his body, placing his back feet alongside his torso and shifting around until he was resting flat on his belly with his front legs (formerly his arms) also pulled alongside him in what was becoming more obviously a feline resting position. Deep in sleep, he shifted his haunches around uneasily as something began to press against the back of his shorts, then settled comfortably back into place as a growing tail burst through the fabric and more or less disintegrated what was left of them, curling around his body as it formed a characteristically leonine tuft of dark hair at the end.
Next to change was his head. In one sense, this was a less radical change, since his face remained completely human except for the way his canine teeth became full-fledged fangs, his tongue took on a rougher, sandpapery texture, and the rest of his teeth got a bit sharper. On the other hand, he might not have seen it that way had he been awake; as his dark, wavy hair grew longer, spilling down his neck and draping loosely over his shoulders in the back and across his forelegs in front, his face softened, becoming a bit rounder, with the gently sculpted lines of a young woman's face. It wasn't long before his body followed suit, his still-human genitals withdrawing between his hind legs, becoming definitely female, and being hidden from view by her new tail.
For a minute, it seemed as though the changes were finished, but something - two somethings - began to strain at the back of her pajama shirt. The relatively loose fabric stretched a fair ways before finally giving out as two great brown-feathered wings exploded from just below her shoulders. Jon shifted a little in her sleep, raising her head a little and mumbling something unintelligible, before stretching her new wings, folding them up against her sides, and laying her head back down on her forepaws. The newly-minted sphinx drew a deep breath and then dropped back into a deeper sleep.
