Mary decided to go with the gender vial, she was curious about it. A vial sat next to it to reverse it's effects.
Mary drank the whole potion as she felt tingly all over, her long hair was instantly sacked into her head but soon reappeared as a trail of short hair trailing from the top of her head to the tip of her tail.
Her formal adjusted a bit as her body became more broad and muscular but you could barely tell because of the fat that covered it.
Her neck bulged barely as an adams apple formed, she belched deeply to confirm that her voice has changed.
"Excuse me" She said in her new deep voice.
The feeling seemed to stop in her crotch as her clit began to grow out to a massive length and girth of three feet long and two feet thick, although she (now he) wasn't erect yet.
It soon reshaped it's self into a large dragon penis, soon more uncomfortable feeling arose as two beach ball sized testicles dropped into a large scaled sack.
He waddled over to a mirror as close as he could to see himself fully.
"Wow..." Mary said in disbelief
"I guess I should have a new name now huh? I'll go with...Mark!" Mark said happily
He looked at the reversal vial and made a note for later.
Just then someone entered through her front door...