Once her sister had fled to the bathroom, Mary turned her attention back to the box containing the vials. Faye's words about being able to become anything echoed in her mid as she looked over the seemingly infinite amount of options presented to her. She thought about what she wanted to be, and the answer she eventually came to was simple: she wanted to be bigger.
Unfortunately, while drinking the “growth” vial seemed like the easiest option, if she grew much taller than her already massive 8'3'' stature she would find the her house collapsing under her sheer size and while the thought of that DID send a pleasant shiver down her back, it would only create more problems down the line. However, “bigger” didn't necessarily mean “taller”. With this thought in her mind, Mary grabbed two vials and mixed them together.
Once the two potions had fully mixed together she immediately quaffed the contents of the beaker, grinning at her idea. If she couldn't get taller, she could get LONGER. To this end she had mixed the “leg” and “snake” vials together and was now waiting for them to take effect.
Her transformation began with sapphire blue growing down her legs, followed quickly by her thighs beginning to fuse together. Realizing that she was about to fall over once her legs had fully merged, Mary quickly flopped her body down onto the bed before she continued to watch her changes. Her legs were soon nothing more than a two-foot diameter scaly snake tail, with the scales on the underside being a lighter shade of blue than the rest. The scales stopped at her waist in the front, her engorged pussy now bulging out of the front of her tail, while in the back her scales stopped a bit lower, keeping her glorious ass fully intact. Of course, the piddly four foot long tail Mary now had was not the end of her changes, her new appendage began to rapidly grow outward. It quickly reached the far wall of the bedroom and changed direction, moving along the walls as it stretched further and further, somehow managing to avoid damaging any of the furniture in the process. Soon the tail had made a full lap around the room and yet it still continued to grow, simply stacking atop itself as it went.
Mary meanwhile, had begun masturbating, so aroused was she by the feeling of her tails growth. She had her full fist shoved into her pussy, orgasm after orgasm passing through her body as her tail began it's third and final lap around the room, stopping at a mind-blowing one-hundred and fourteen feet long. Once her growth had stopped, Mary's lust began to wind down, and soon she was laying flat on her bed, panting. Her eyes then wandered back over to the vials, and she began to ponder just how she and Faye were going to use them.