POOF!
He was surrounded by a thick cloud of glittering smoke. He coughed into his hoof, eyes shut tight. The back of his throat was gummed up. He cleared his throat, but it didn’t help. His voice was weak, hoarse and strained. He cleared his throat again, to no avail. He muttered something to himself, and then froze in horror. When he spoke, he didn’t feel the familiar soft, baritone vibration of his voice on his adam’s apple. He said something else, gasping and cutting himself off mid-sentence at the sound of his own voice. It wasn’t strained, or hoarse; it was higher-pitched. Feminine.
He quickly reached his forehooves up to his face, feeling around. His muzzle felt smaller, more rounded and demure. He lifted a lock of his mane, thinking it looked longer than he remembered it being. He felt his way downward, his hooves running down his slender midsection before they glided over the rounded curves of a couple plump, child-bearing flanks. He gulped. His hooves quickly shot around front and hooked their way between his hind legs, looking in vain for the last, definite piece of his masculinity, but it was all gone.
Parchment had turned female. He was a cute mare from nose to tail. He let out a small, feminine whimper in fear. Something told him that it wasn’t just going to end here.